This is the first picture I got from the breeder I got the project from. Approximately half the clutch were normally pigmented black and silver/tan babies, and the other half had the reddish color.
My original "Caramel type" female.
Jungle Jaya Jaguar - This is BIG, my holdback 2010 male. He is about four months old here.
Pile of babies 2010.
These snakes are 37.5% Diamond, 12.5% Jungle and 50% Coastal
Caramel Type Jaguar - This male should be ready to breed for the 2012 season.
Breeding Carpet Pythons
Before You Read... Breeding carpet pythons is a fairly straight-forward process and the snakes do most of the work. With this page, I've tried my best to not only tell you what works for me, but the logic behind what I'm doing. Unless you have an identical facility in an identical climate, you will still need to taylor a system to work for you. By reading this, hopefully you will be able to adapt some of the principals I explain to suit your particular application/location.
Read the whole thing! This guide was written to be read in order. As tempting as it may be to read only the parts you have a question about, reading this guide from start to finish is the only way it's going to really make sense.
Python Breeding Rule #1 - There is no recipe. Before you read anything here, I want to point out the most important thing there is to know about breeding snakes. There is no recipe.
If you've been researching the subject any time at all, you undoubtedly know that everyone seems to have a different way of breeding their snakes and they all seem to work. This is because there are so many variable factors, one of the most significant probably being the natural climate in one breeder's area versus another. In other words, what works great for one person may not work for another...in fact, it rarely does.
If you're looking for a breeding "recipe" that works for everyone, you won't find one. In that regard, breeding is more of an art than it is a science. Ultimately, the animals are in control and all we're doing is providing stimuli to get the animals to do what we want. Sometimes they do, sometimes they don't.
This page was written to help you understand the breeding process better, not to tell you how big your female should be, when to start cooling or what the temperature should be. That being said, I will try to provide an objective look at all aspects of breeding carpet pythons, but the best advice I can give anyone is this; Pay attention to your snakes, always try to keep learning and always think for yourself...in other words, don't do something against your better judgement because that's what someone told you to do.
So, how big or old should my female be? That question is asked all the time and the truth is, I don't know and neither does anyone else. I put it here at the top, not because it's important, but in order to get it out of your head before you read the rest of this page.
That being said, here's what I can tell you. Carpets come in many different sizes and as we all know, the size of adults will vary amongst individuals of the same subspecies. I personally feel that if you're going to base your decision on a number (something I don't generally like to do), age is probably a better number to look at. I personally think it's best to wait until a female is at least 3 years old, if not older. Some people breed them a year sooner, but in my experience, waiting an extra year usually translates to roughly twice the eggs on the first clutch and larger subsequent clutches. To me, nothing is worse than a female carpet who produces a tiny number of eggs (like a ball python). The most important thing, regardless of size or age, is that a female is physiologically ready to reproduce. I personally think the overall condition of a female is the most important thing to consider.
How big or old should my male be? That's another one I can't really answer. Some individuals will start breeding when they're small and young, while others don't seem to kick in until later. I've bred male Irian Jayas and Irian Jaya Jaguars at no more than 750-1,000 grams and 18 months of age. I have limited experience with Jungles, but have friends who have successfully bred a male Jungle at roughly the same size and the same age. With coastals, I like the males to be a little larger (so they can handle a larger female), but I would say the minimum age is about the same, although getting them up to sufficient size by 18 months may be difficult.
What is Temperature Cycling or "Cooling"?
This is essentially the process of cycling temperatures to simulate seasons, which trigger your adult carpet pythons to begin the reproductive process. Some people believe that cooling also triggers the male to produce viable sperm, but studies have shown that males don't always need to be cooled to produce viable sperm. I've also successfully bred males, on several occasions, which had not be cooled previously. Some people even say that cooling is not necessary to breed carpets and that may be true with certain specimens, but I like to cool all of my carpets, so that I know they're all on the same basic schedule.
Remember, the idea of cooling is to get your snake's body to recognize that winter is coming, winter is here and then later, spring is approaching. There are many ways to do this, there is no recipe and all you need to do is provide enough of a difference that your snake's body recognizes the different seasons that you're essentially creating in its cage. Truth be told, I really don't think the exact temperatures really matter.
When should I start cooling? I can't tell you that without knowing where you live and when your winter really hits its peak. Try to go along with the temperatures in your area, but make them carpet python temperatures...in other words, take the temperature regime I gave above and mold it to fit the timeline of the fall-winter-spring where you live.
Throughout most of the year, I keep my carpets at a constant day/night temperature with a basking area around 88-90F and the ambient temperature is in the mid 70's to low 80's. I do not drop the temperature at night during the off-season.
When I start cycling or "cooling" my carpets, I keep the daytime temperature just like I would any other time of the year, but I turn the heat off at night. Below I will give you a basic timeline of how I do things here.
Sample of Temperature Cycling in my Collection
Important Note About Dates Again, this is not a recipe, so keep in mind that the dates are not important...they're simply what happens to work here in the Midwest. Also remember that the night-time temperatures will vary a bit from one day to the next (either naturally or by my doing) throughout the breeding season. Feel free to change things up a bit throughout the season and tailor it to your needs. The only important thing is that your snakes sense enough of a change in climate to get them to react accordingly.
January 1 - January 15 2 weeks with 18 hours of heat and 6 hours without heat. This is the time when I stop or reduce feeding and let the snakes get adjusted to not having any heat at night. At this time, I let the room dip into the 70-75 degree range at night.
January 15 - February 15 Approximately one month (4-5 weeks or so) with 12 hours of heat and 12 hours without heat. This is basically the "dead of winter" for my carpets. Night time temps are generally 70-75F...however, now that the snakes have had a couple weeks to adjust to having no heat at night, I will let temperatures get into the 65F range on occasion by closing off the vents in the room and/or opening a window. I never let it get into the 60's for more than one or two nights in a row. I am able to get away with such cold temperatures for short periods because the snakes are still able to warm up during the day. If I were not giving them "normal" day-time temperatures, I wouldn't let it get quite so cold.
February 15 - March 1 At this point, I go back to 18 hours of heat and 6 hours without heat. The night-time temperatures are generally still pretty cool and I will hit them with the occasional 65 degree night while the weather allows, but it's usually starting to warm up here by March.
March 15 through the end of summer At this point, they still get 18 hours of heat and 6 hours without heat...but now the night-time temperatures are quite a bit warmer than they were during the dead of winter and I quit letting night temperatures drop below 70-75F. This is when most people would quit cooling and go back to 24 hours of heat, but I like to keep the night drop going all season. By mid-March, it usually only gets down to 75F in my snake room at night, so I figure it can't hurt. Even gravid females do just fine with a drop into the mid 70's at night. I leave the night drop intact throughout the summer or until I'm absolutely sure that breeding season is over. My latest clutch came in late July last year, so don't count anyone out too early! *The reason I leave the night drop going all summer is this; This is a warm time of year and female snakes can and will reabsorb follicles if temperatures get too warm. If I were to put the heat back on 24 hours a day, I could easily miss out on some late clutches.
UPDATE I am no longer "cooling" my pythons. All of the carpets, balls and blood pythons produced in 2010 were produced by adults who had access to basking heat 24/7/365. Only the ambient room temperature dropped, and only by 5-10 degrees. I did the same in 2011 and seem to be having a great year.
Introduction & Courtship The first thing I do is remove any hide boxes from the cage. This way, I can see what's going on and I don't have to worry about one snake squeezing into a hide box and alienating itself from the other. I always introduce the male into the female's cage. I start introducing males periodically as soon as I start the cooling period and I move them around a lot. I usually remove all hide boxes when introduction begins. This gives me a better chance of observing copulation and also allows the snakes to come into contact with one another more often. When a male is interested in breeding, he will spur the female's back...usually on the posterior (rear) third of the body.
If the female is receptive and giving off pheromones to signal the male that she's ready, they should copulate within 24 hours. You will usually see copulation, but not always. Some males are sneaky...in fact, I have males that sired several clutches before I ever caught them copulating.
How often should I introduce the male? And how long do I leave him in? If I see a male breeding a female, I know he's breeding her and I will leave him in until they no longer show interest...usually a few days. Then I remove him and put him with another female or into his own cage for a few days. If the snakes go to opposite ends of the cage and show no interest at all, I usually will take the male out within 24 hours and try again in a week.
If you have a male that you know will breed out in the open, it makes it a lot easier to know what's going on. However, if you're working with a new male that you haven't bred before or one that is shy about breeding out in the open, you should leave him with the female for several days (if not a full week) at a time on a regular basis. With a shy male, all you can do is hope that he does what he's supposed to do.
My male won't breed! This could be true, but it's most likely not your male. When a female has follicles that are ready to be fertilized, she will emit pheromones or scents that arouse the male and tell him that she needs to be bred. By using an ultrasound to look at follicle size and compare it to breeding activity, I've discovered that even the best male breeders won't breed a female if she's not ready. For those of you with access to an ultrasound unit, breeding activity seems to pick up when follicles reach the 16-20mm range.
In nature, males sometimes combat to determine which one is stronger and ultimately, which one gets to breed a female. The combat sequence is usually entails the males "wrestling" by twisting around one another and trying to pin the other to the floor.
Studies have shown that testosterone levels actually become higher in the winning snake and vice versa in the loser, which could very well have an impact on their desire to breed. That being said, it can go both ways, so be careful not to let things get too out of hand...especially if you want the smaller male to be the on who ends up doing the breeding. I typically don't combat my males, but this can sometimes be useful to get a male going. On the rare occasion that I do combat two males, I try to put the male that I want to breed in with a smaller male (preferably a proven breeder) and I always separate them before someone actually loses.
If you decide to try combating your males, always stay present while they're in a cage together. If things get out of hand, they may bite each other, which can result in severe lacerations (which could require stitches) or even kill one or both males. In nature, the loser can flee into the woods...in a cage, there is no such option.
Feed to Breed Because I maintain daytime basking temperatures year round, my adults are able to feed and digest meals throughout the entire breeding season. That said, I still tend to feed sparingly during the breeding season. Some breeders offer a lot of food to females once they start warming up. Instead, I typically only feed my snakes about once a month, if even that. I can do this because I try to have my females in prime condition (but not fat) before I start cooling. Some of my females don't get fed at all during breeding season. In fact, my Irian Jayas rarely need to be fed at all until after they lay eggs, as they breed the earliest. With other carpets, I typically have time to get a few small meals into them and I will then feed them sparingly after that.
Males expend a lot of energy during breeding season, so it's important they're at least given the opportunity to feed. My males are generally fed as needed, but no more often than that - in other words, I keep an eye on them, and if they start to look thin, I feed them...if not, I might not. That's why I like snakes! :-) The common belief is that males go off feed during breeding season, and this may be true with other python species, but the majority of my male carpets seem to feed year round.
Again, there is no "recipe", and that includes when or how often to feed breeding snakes. This is why it's important to observe your animals and let them tell you what they need.
For example, if a female doesn't seem to be producing follicles (males show no interest in her), I will feed her a little more heavily (still keeping each meal small) in hopes of telling her body that spring is here and food is readily available and ultimately, that it's a good time to reproduce. I try to keep meals small because if they are too large, there's a chance that she won't have room in her body for developing eggs and could have reproductive complications, such as egg binding. I've had several instances of egg-binding and I have to wonder if it was due to females being fed too much during the spring.
The Reproductive Process
Reading Your Females The most important thing you need to be good at is reading your females...and unfortunately, the only way you'll get good at it is with experience. Once you learn to recognize the slight behavioral and physical changes that occur, it's a lot easier to know what's going on with your females. The signs aren't always obvious and it will take some time to get good at recognizing the signs, but it gets easier with every clutch.
That being said, I will try to explain here what you're going to be looking for.
Getting Your Bearings To get an idea of where a female is in the reproductive process, the first thing I do is introduce a male. Most males will only breed a female if she has fairly mature follicles and is emitting pheromones to signal him that she is ready to be bred. Once your snakes start to copulate, you should start watching for the rest of what we'll call landmark signs, which I've outlined below. Of course, some males are sneaky and you won't see them copulate, so always pay attention to your females!
Stage 1 - Follicular Development
* What are follicles? If a female has sufficient fat stores and has been sufficiently cycled (and sometimes even if she hasn't), she will begin to produce follicles. Follicles are essentially eggs that are in the developmental process. Unlike mammals, which are born with all the eggs they'll ever have, reptiles generate new eggs each time they reproduce.
* Follicle size and what it means... If you have access to an ultrasound imaging unit, you can actually see how many follicles are in your female and how big they are. I was fortunate enough to use an ultrasound unit a few times in 2006 and was able to note follicle size and observe corresponding behaviors. I discovered that most of my carpets had 5-6mm follicles when cooling began, but some of my Irian Jayas were already two to three times that size. In just about every female, once the follicles reached 18-20mm in size, the female seemed to be emitting pheromones and my breeder males became very interested in copulating with them. I noted that ovulation occurs once the follicles reach about 25mm in diameter.
* Palpating for Follicles If you're like most of us and don't have an ultrasound unit, you can try palpating your females by wrapping your hand firmly around the female's mid-section and letting her crawl through your hand. Wrapping a paper towel around the female can help her slide through your hand more smoothly. It should be noted, though, that this is very difficult to do with carpets due to their size and the number of follicles/eggs they produce. With smaller carpets, though, this can be an effective way to see if your female's follicles have any significant size to them. As a general rule of thumb, if you can feel follicles, they're probably pretty big (at least 15mm), so get a male in with the female ASAP!
Stage 2 - Pre-Ovulation Swelling Once your female has been bred and is going to ovulate, she will start showing signs. These signs usually start with slight swelling in the posterior (rear) third of the body. This swelling isn't necessarily a visible lump, but rather the body starts to feel feel firm and "tight". The scales may start to spread out a bit at this time (but not always) and the body will take on a more rounded (as opposed to oval) shape. Another sign to look for is body posture, as females will usually begin lying in a coil, sometimes with the ventral scales positioned perpendicular to the floor of the cage.
At this point, the female will be putting off a high amount of pheromones and the follicles are still able to be fertilized. As such, I always try to put the male in and let them copulate as much as possible during this period. I typically leave the male in until the snakes are no longer showing any interest in breeding.
Stage 3 - Ovulation Ovulation is the point at which the follicles move out of the ovaries and into the oviducts, where they'll be held until they're laid. At this point, there's no point in keeping the male in with the female. The follicles are now officially eggs and should have already been fertilized. That being said, if you're unsure about it being ovulation, you might want to leave the male in with the female, just in case.
The ovulation process is noted by visible swelling that occurs while the eggs are moving into place. This process usually happens in less than 24 hours and the swelling will be all but gone in a short period of time. That being the case, it's easy to miss ovulation if you're not careful to observe your females every day.
Stage 4 - Pre-Lay Shed A few weeks after ovulation, the female will go opaque and shed. Once the female sheds, you're just another 3-4 weeks away from getting eggs. At this point, there will be a nice, round look to the posterior third of her body and scales will usually start spreading apart.
About a week before laying, the female may become restless and when she is resting, you may observe her lying inverted (belly up). At this point, you will need to start checking for eggs on a regular basis.
Egg Laying Once a female has her pre-lay shed, I place a nest box into her cage. For a nest box, I generally use a 15 quart Rubbermaid or Sterilite container with a hole in the lid. Inside the box, I place crumpled or shredded newspaper as a bedding material, since I will be removing the eggs as soon as they are laid. If you aren't sure that you'll be able to get to the eggs within 24 hours or if you're going to try maternal incubation, you may want to use dry sphagnum moss (not peat) instead.
If you catch your female in the process of laying her eggs, try not to disturb her. Let her finish and coil around the eggs before you try to take them.
Female pythons can be very protective of their eggs, although I will say, female carpets are surprisingly easy to deal with when removing their eggs. In fact, female ball pythons are a lot more aggressive as mothers, in my experience. In any case, unless you enjoy bleeding, I recommend putting on a pair of leather gloves. Aside from the fact they'll protect your hands from a bad bite, thick gloves also reduce the heat signature put off by your hands and may help prevent the female from striking at all.
Incubation Temperature I prefer to artificially incubate my python eggs between 87.5 and 88 degrees Fahrenheit. This temperature is inside the incubator itself and not the egg box. Some breeders like to measure egg box temperatures, as eggs tend to generate heat as they near hatching. I incubate multiple clutches at a time, so I've found 87.5F to work well as an overall incubator temperature. This usually results in a 58-60 day incubation period and large, robust hatchlings. You can incubate at a slightly higher temperature for a slightly shorter incubation (55 days or so), but you have to be careful that the clutch doesn't overheat once the eggs start generating heat. In other words, you will have to be sure to measure the temperature inside the egg box.
Artificial vs. Maternal Incubation By going with artificial incubation, I typically achieve a perfect hatch rate (of fertile eggs) and my female breeders are able start eating immediately, which allows them to recover much faster than if I were to let them tend to their clutches. I feel this extra couple months of eating gives my females a better chance of breeding the following year. Aside from the recovery aspect, there's also the prospect of cage and nest box conditions being less than optimal and ultimately losing good eggs. In nature, a female can choose the perfect nest site, but in captivity, she's stuck with whatever I provide.
I'm not saying maternal incubation is a bad idea...those are just the reasons why I prefer artificial incubation. That said, I'm sure maternal incubation can be very rewarding experience in and of itself and I'm sure I'll try it sooner or later.
Hardware for Artificial Incubation There are two pieces of "equipment" you need when incubating your eggs...an incubator and an egg box. There are a lot of misconceptions about the specific roles that the incubator and the egg box play. Here, I will explain the role of each component.
1. The Incubator - Temperature Control The incubator is simply a heated, insulated chamber. Its only function is to maintain a set temperature...nothing more, nothing less. There are several commercially made incubators available, but I've always used ones that I've made. I personally use a refrigerator and a cooler, both of which have been converted to incubators by simply adding heat tape to the floor and back wall. I just attach a proportional thermostat to control the temperature and that's it. Refrigerators make a great incubator because they're already well insulated and finding a broken one is not difficult at all. I've made no mention of humidity here because that is not the incubator's job.
Why do I see some incubators with a big pan of water at the bottom? You may sometimes see a pan of water at the bottom of an incubator. This practice is supposed to be a means to hold heat more steadily within the incubator, as the temperature of water changes much more slowly than air. If your incubator loses a lot of heat when it's opened and takes a little while to warm back up, you may want to place a tightly sealed container of water at the bottom of your incubator. Some breeders have seen this and apparently misinterpreted the pan of water as a mean s to control humidity within the incubator. Having an open pan of water inside your incubator is actually a bad idea, as condensation build-up on the walls or ceiling of the incubator could potentially cause a short in any exposed electrical connections inside the incubator. In addition to being a hazard, controlling the humidity inside the incubator itself is completely unnecessary (if your egg box is set up properly).
2. The Egg Box - Humidity Control While the incubator controls the temperature, the purpose of an egg box is to control humidity and to prevent the eggs from drying out. For an egg box, I use a tightly sealing Rubbermaid food container as shown here.
There are many ways to set up an egg box, but I'm just going to describe what I do...which I've found to be the easiest and most fool-proof way to get a perfect hatch rate (provided all eggs are healthy).
I fill the egg box with about 1.5" of perlite and then add lots of water...to the point that the perlite is completely soaked. I then add two layers of plastic grid, which can be purchased as "egg crate" style plastic light diffuser from your local hardware store or home center. The purpose of the plastic grid is to keep the eggs from coming into contact with the wet perlite. This is basically a spin-off of the "no-substrate" incubation method, but I've chosen to add perlite to prevent the water from splashing up onto the eggs when the egg box is moved. This method is my favorite because it requires no guess work as to how much water to add to the medium.
I drill a 1/4" hole on two opposite sides of the box for air exchange. If I were using a different method (such as eggs sitting directly on damp perlite), I would make the holes much smaller or do away with them completely.
Hatching Begins After roughly 55-60 days, the neonate carpet pythons should begin to emerge. They begin by slicing the egg with their egg tooth, a process referred to as pipping. As soon as the first neonate pips the egg, the first thing I do is separate the eggs from the pile. The eggs should be pretty easy to separate at this point, but be careful not to tear them. I always mark the top of each egg after they've been separated, as placing an egg upside down is a bad idea.
As you can see by the photo here, once the snakes start to breathe on their own, I will make the hole bigger to ensure they find their way out without getting wrapped up in their umbilical cord, etc.
Care should be taken to avoid cutting the membrane that sits just beneath the egg shell. This membrane is lined with veins, which begin to atrophy (die off) and turn grey shortly before the neonate emerges. Although I've accidentally cut through a live vein on more than one occasion, I still try to avoid it. Because incubation is almost complete, cutting into the membrane itself isn't a huge issue at this point. Just avoid any live veins (which are still red) and try to leave as much of the membrane intact as possible.
To avoid cutting into the membrane, I pinch the egg and roll it in my finger a few times to separate it from the shell. The eggs will be very "deflated" looking by this point, which makes it easy to pinch the shell away from the neonate inside. I then proceed to make a V-shaped incision in the part of the shell that I have between my fingers. Once I've made the initial incision, I reach into the hole with the round-tipped scissors and further separate the shell from the membrane around the top of the egg. As long as there are no longer a lot of live veins, I usually try to cut away a bit of the shell (the size of a quarter or slightly larger) to ensure that the neonate can emerge without incident.
Pippin' ain't easy... If you're not familiar with this process, just don't do it. If absolutely necessary, I recommend enlisting the help of (or even paying) an experienced breeder to help you the first time you manually pip an egg, even if only for moral support. It's not brain surgery and the neonates aren't as delicate as one might think, but scissors and baby snakes can obviously make for a hairy experience the first time you do it. If you can't find someone to help and you don't feel comfortable, you can skip the manual pipping all together.
Breathing Begins When the neonate is inside the egg, the egg shell essentially brings oxygen into the blood, which the snake then gets by way of its umbilical cord. Once the veins inside the egg and around the membrane start to turn grey, the neonate will need to begin breathing on its own. Sometimes, if the egg is pipped a bit early, the neonate will poke its head out and start breathing anyway. However, if you see a neonate keep its head buried inside the egg, don't worry. It is still getting oxygen from the blood coming in from the umbilical cord.
Hanging Out and Absorbing Yolk After poking their heads out and beginning to breathe, neonate carpets will typically hang out in the egg for a couple of days (give or take) while they absorb what's left of their egg yolk. Try not to disturb them too much during this time. If you disturb them, they may try to flee and take their yolk sack with them. Once that happens, the umbilical cord will dry out and the yolk sack will fall off, cheating the neonate out of vital nutrients...ultimately giving you a smaller, weaker hatchling to deal with later. As you will undoubtedly learn, neonates who absorb more of their yolk tend to grow faster and feed more readily during the first few months.
The snake at right had actually swallowed its own tail all the way up to the umbilical cord (about 1/3 of its body). I carefully removed the snake's butt from its mouth and it eventually left the egg and took to eating rats just fine. :-)
Leaving the Egg Once the baby snakes emerge, I take them to the sink and rinse them off as best as I can. This is the best time to sex a carpet python, so before I walk away from the sink, I sex the snake by way of popping, or manually everting the hemipenes.
Determining the sex of hatchlings... As some of you are well aware, sexing carpet pythons can be tricky. Some people believe that probing is the best way, and it is with most python species, but female carpets are notorious for probing to similar depths, regardless of sex. As such, I ALWAYS sex new hatchlings by popping (or everting the hemipenes) as soon as they leave the egg. When they first hatch, they have very little muscle control and easy to visibly sex males AND FEMALES by way of popping. The hemipenes on males are everted quite easily and on females, you will be able to see a small white bump where each of the hemipenes would normally be on a male. If you don't see the white bumps, you most likely have a male that's just difficult to pop. I have been doing this for several years now and out of hundreds of neonates, I have yet to make a mistake. Have me pop a clutch at a month or two of age and then it's another story. This is why I can't stress how important it is to sex them as soon as they leave the egg.
Getting Hatchlings to Feed It's pretty easy to get hatchling carpets to feed on live rat pinkies or mouse hoppers, but they'll pretty much ignore something smaller than a mouse hopper.
I don't have a good supplier of live rodents, so I try to start everything on thawed prey. It's preferable to get them started on rats, in order to avoid switching issues later, but mice will work too. I've started hundreds of babies on thawed rat pink and the biggest key is that the thawed pinky should be warm to the touch...this stimulates those little heat pits on the snake's snout. After thawing a pinky in hot water, I will start by just showing the prey to the snake, make sure the snake notices and then set the prey item down a few inches away. A lot of baby carpets will eat the rat pinky overnight.
Go Fishing! If after 3 times, the above method doesn't work, I will try tease-feeding. Rather than dangling the pinky overhead (which must seem like a big flying predator to a baby carpet!), I try to drag the rat pinky around the floor of the cage using 18" hemostats. I'll try lightly touching the prey item to the snake's tail will sometimes get a response.
Don't Over-Do Feeding Attempts We generally only try to feed once every 3-5 days, so as not to stress out babies that aren't ready yet. For EXTREMELY difficult feeders, a last resort before trying assist/force feeding is a thawed day old quail (available from Rodent Pro). This will be a huge prey item, so it's important that the snake isn't allowed to get thin before trying a day old quail.
How long can a hatchling go without food? I can't say how long it's safe for a hatchling to go without eating, as I don't know how much yolk it absorbed before leaving the egg. The most important thing is to watch the snake and make sure it doesn't get noticeably thin. At that point, the metabolism slows down and the snake's hunger and feeding response will be diminished. A hatchling in such condition will most likely die unless small meals are force fed. If the snake does not shed within 2 weeks of hatching, you should start offering food once a week anyway.