Snakes are fascinating creatures with diverse and unique reproductive methods. Multiple factors influence snakes’ reproductive strategies and success, including seasonal shifts, environmental temperatures, and food availability.
If you’re curious about how this affects snake breeding in captivity, keep reading! In this article, I cover all the important details you need to know to start breeding your own snakelets.
Note that this article doesn’t refer to a given snake species, but covers snake reproduction at large.
Preparing for Breeding Season
In the wild, most snake species breed during early spring or summer. The exact months of the breeding season depending on the species and its natural habitat. But generally, the breeding season coincides with marked increases in temperature.
In captivity, there’s theoretically no breeding season. You don’t have to wait until spring because you have full control of the temperature in the snake’s enclosure.
So, you can encourage your snakes to breed at any time by manipulating their environment. Here’s how to do it—
First, you’ll have to induce a state of hibernation in your breeding snakes. That’s because the breeding process depends on seasonal shifts. The snakes must hibernate over the winter before they’re ready to reproduce.
This colder period also leads to increased fertility in female snakes, so it’s an important step when preparing them for the breeding season.
After a few weeks of cold exposure, you should gradually warm the enclosure until the environment reaches optimal temperature for breeding. This simulates the natural seasonal shift from winter to spring.
Follow the steps below for a smooth operation; this should help kickstart your snakes’ breeding:
- Keep your snakes separate during the cooling phase.
- Provide your snakes with a soft substrate for burrowing; that’s where they’ll hide during hibernation. You can also move your snake to a small container instead of the enclosure. Just make sure to include the substrate in the container. A separate box can work better than a vivarium, as it’s easier to move around to cooler locations around the house.
- Gradually reduce the snake’s food for the following two weeks before changing the temperature.
- Keep a water dish in the enclosure at all times throughout the hibernation period. Even inactive snakes should get in some hydration at least once every two weeks.
- Drop the enclosure temperature slowly, a few degrees per day, until you reach optimal hibernation temperature. For most snake species, that’s around 60°F day and night.
- Keep the snakes in stable low temperatures for 60-90 days.
- Maintain minimal visible light exposure for your snake throughout this process.
- After the 60-day mark or up to 90 days, you can return the enclosure temperature and light to normal. Increase the temperature gradually over the following 3-4 days. During the breeding season, snakes thrive in temperatures between 82-90°F during the day and 73-78°F at night.
- Begin feeding your snakes frequent meals of small live prey. Increase the portions to normal amounts as the snake’s appetite picks up.
- The snakes are ready to breed once they complete their first shed post-hibernation. After that, you can place the breeding male and female together.
If both snakes you introduce are sexually mature, healthy, and fertile, they should start reproducing. The process usually takes 4 hours or more. Some snakes might even stay connected for days!
Try not to separate the snakes until they let go of each other, as this can lead to ineffective breeding. Patience is key at this stage.
Finding a Mate for Your Pet Snake
For the highest success rate, you must choose snakes that are sexually mature, healthy, and, of course, compatible. So, you’ll have to determine your snake’s age, sex, and health before choosing a breeding pair. This all depends a lot on your snake species.
Small snakes like hognoses, corn snakes, and children’s pythons typically reach sexual maturity after roughly two years. Larger snakes might take four years or more until they become adults. If you don’t know your snake’s exact age, you can also measure its length and weight.
Compare those to the standard length and weight in adults of the same species. A young adult hognose, for example, is roughly 16-22 inches long and weighs 4-5 oz. On the other hand, a large snake, like a ball python, should weigh at least 18-50 oz when it reaches sexual maturity.
Size differences depend a lot on the snake’s sex, as males are generally longer and heavier than males. This brings me to the next point— sexing the snake to find a breeding pair.
There are a few ways to do this:
- By appearance (females are larger; in some species, males and females display different colors)
- By tail shape (male snakes have longer and wider tails that appear thick and blunt; female tails are shorter but thinner and pointier)
- Using a snake sexing probe. This method is more technical, and you’ll need special equipment. The snake sexing probe is a thin, small metallic instrument with a ball tip. The ball tip can come in various diameters, each suitable for snakes of different sizes. This is the most accurate way of sexing snakes, but it’s also riskier because an inexperienced hand could hurt the snake. You must also do this when the snake is awake, and it’s almost guaranteed the snake won’t cooperate. If you’re not confident you can do this, consider contacting a reptile veterinarian for help. When probing the snake, he or she will insert an appropriately sized, sterilized, and lubricated probe inside the snake’s cloaca (the opening towards the tail), pointing it toward the tip of the tail. If the probe slides no deeper than 1-4 subcaudal scales, the snake is female. In male snakes, the probe should slide between 7-15 subcaudal scales deep.
Finally, you should determine the snake’s health status. This is important, especially before inducing brumation. The snakes will go for prolonged periods without much food or water. So, you need hardy specimens that can withstand this process.
The female should also be nourished and at a healthy weight for optimal fertility and clutch size.
Monitor your snakes for a few days to observe any warning signs. Also, keep an eye out for worrying symptoms during the brumation period.
A snake might not be apt for breeding if it:
- Appears lethargic in normal temperature conditions (lack of movement, weak reflexes when picked up, prolonged hiding)
- Displays poor appetite or weight loss (visible spine and ribs; the body sides might appear sloped instead of rounded)
- Has digestive issues (vomiting, runny stools)
- Shows signs of dehydration (sunken eyes, problems shedding, stringy saliva, sticky mouth)
- Appears to have an infection (pinkish underbody skin, skin blisters, bumpy scales, swelling in various parts around the body, unusual discharge coming from body orifices)
If you notice any of these unusual signs, contact a veterinarian immediately! Your pet snake might be ill from a life-threatening condition. Such cases require urgent attention.
Reproduction Processes Unique to Snakes
The vast majority of snakes reproduce sexually, so it takes one male and one female snake for fertilization to occur.
Sexual reproduction usually occurs during the warm season, when the adult snakes are most active and food is abundant in their environment.
This much is generally true for most animal species. However, snakes also have a few traits that set them apart. First, snakes don’t rely on visual cues when choosing a mate. That’s because most snake species display no apparent signs of sexual dimorphism.
Male snakes have two reproductive organs called hemipenes, which can pop out of the cloaca during reproduction. Unless the male snake is trying to reproduce, these organs are tucked inside the body, so both sexes look indistinguishable. Female snakes have ovaries, which connect to the cloacal opening through an oviduct.
So, how do snakes know to pick a mate? Turns out, snakes have somewhat of a “sixth sense.”
They possess a vomeronasal organ that sits at the base of their nose. This organ plays a crucial role during mating, as it allows male snakes to “smell” female pheromones.
During the breeding season, female snakes produce more estrogen to attract a mate. Based on these pheromones, male snakes can tell the female snake’s sex, age, health, and reproductive fitness.
When mating, male snakes wrap themselves up around the female and lay their heads on the female’s back. The reproduction process takes a long time, so the snakes might sit in that position for hours, or even up to an entire day.
When reproduction is over, the male snake releases a gelatinous “mating plug” to block the female’s cloaca. This ensures the female snake doesn’t reproduce anymore during the same breeding season. The snakes separate, and the female now carries the fertilized eggs.
Depending on the snake species, the female snake will either lay eggs or give birth to living young. Some snakes have the rare ability to produce asexually.
They do so through a biological process called “parthenogenesis,” in which female snake eggs develop into embryos without fertilization.
This reproductive process is extremely rare in animals, and mostly present in invertebrates. The best-known example of a parthenogenetic snake is the brahminy blind snake (Indotyphlops braminus).
Live Births vs Egg Laying in Snakes
We can separate snakes into two main categories, depending on their reproduction style. First, there are egg-laying (oviparous) snakes, which make up 70% of all snake species.
Upon mating, the female snakes produce eggs. The fertilized eggs stay inside the female’s oviducts for two weeks after mating.
After the eggs are sufficiently developed, the female lays them in a warm, humid environment. Egg-laying snakes can produce clutches of 2-100+ eggs, depending on the species.
Female snakes don’t brood their eggs and don’t care for their young, so the baby snakes are on their own even before hatching.
The fertilized eggs contain growing embryos, which feed from the yolk and the white inside the egg. Like in all oviparous species, snake eggs go through an incubation period which typically lasts 60 days.
The incubation and snakelet’s development depend on environmental factors, especially temperature.
Eggs exposed to higher temperatures produce larger baby snakes. Unlike in other reptiles, the temperature doesn’t influence the snake’s sex. The baby snake’s sex is pre-determined at fertilization.
Then, we have snakes that give birth to living young; these are called “viviparous.” They’re very rare, and scientists believe this reproductive strategy evolved to help snakes reproduce in hostile environments.
That makes sense because viviparous snakes are most common in cold climates, where snake eggs couldn’t survive the low temperatures.
After mating, the fertilized reproductive cells implant into the female snake’s uterus. There, they develop into embryos, and then into baby snakes throughout the gestation period.
Unlike in egg-laying snakes, the embryos of live-bearing snakes receive nutrition directly from the mother’s body through the placenta.
After at least three months, the mother snake is ready to give birth. Some examples of viviparous snakes include vipers, garter snakes, water snakes, and boas.
Offspring number and size differ more from one species to another than between oviparous and viviparous snakes.
Problems With Captive Snake Reproduction
Breeding snakes takes some know-how and planning. Inexperienced herpers can still breed snakes successfully but a few concerns arise with improper breeding practices.
Special attention to the environmental parameters, diet, mate selection, and maintaining the breeding snakes’ health is paramount.
If we overlook one or more of the above factors, we might encounter a few problems when breeding snakes in captivity.
Here are the most common issues:
Inbreeding is a serious yet overlooked issue in the reptile hobby. It occurs when closely-related snakes breed together, especially over multiple generations. Think of breeding parent snakes with offspring, or crossing siblings from the same parents, even if they come from different clutches.
This phenomenon leads to something called “inbreeding depression,” which basically means the new offspring suffer because of low genetic diversity.
As the gene pool decreases, the new snakes might suffer from stunted growth, physical deformities, lower immunity, infertility, and various health issues. Clearly, inbreeding has dire consequences for animal welfare.
The worst part is that inbreeding is quite common in the reptile hobby due to small-scale breeding operations and the high demand for new and unique color or pattern morphs.
However, you won’t have to worry about inbreeding if you’re just starting. Just remember to buy new adult snakes to form a breeding pair for your snakelets in the future.
Egg binding happens when a female snake can’t release the fertilized eggs she’s carrying. One reason this happens is due to stunted or anomalous egg development; this extends the gestation period more than what is normally expected. It can also happen when the oviducts or cloaca are obstructed.
This is a serious condition that can prove fatal if untreated. Egg binding can lead to lethargy, lack of appetite, weight loss, muscle straining, and cloaca prolapse (more on this later).
In some cases, the underlying issue that led to egg binding can also progress and cause significant damage to the female snake.
Multiple factors increase the risk of egg binding. The female snake’s age and body size play a role. Young female snakes might have a narrow cloacal opening, which makes laying eggs more difficult. But environmental factors are the most important.
Hydration and diet play a huge role in egg formation. The two weeks in which the eggs form are very taxing on the female snake’s body, and the yolk requires a high amount of calcium to develop.
Egg-bearing will worsen an underlying calcium deficiency, leading to symptoms of anorexia and potential death.
Sufficient hydration is also important to produce uniformly-shaped eggs and maintain internal lubrication— both of these factors play an important role and facilitate egg laying.
Finally, the temperature and substrate are equally important. Female snakes need a warm and hidden spot to start laying eggs.
A cloaca prolapse means the inside of the snake’s cloaca has turned inside-out and hangs outside the body. If this sounds horrifying, it’s because it is. Cloaca prolapse is also a distressing and painful experience for snakes.
This happens in female snakes as a consequence of straining to lay eggs. It commonly coincides with calcium deficiency and egg binding.
Beyond the cringe-inducing mental picture, a cloaca prolapse is terrible in other ways. The soft tissue inside the cloaca can get damaged, infected, and necrotized from the straining and fissures.
Luckily, this issue is easy to treat. A vet might check the snake for signs of calcium deficiency and recommend a supplement to solve the underlying malnutrition. The cloacal prolapse can be fixed with surgery. In severe cases of necrotic cloacal prolapse, euthanasia might be the last option.
A hemipene prolapse is like a cloaca prolapse but in male snakes. The snake’s reproductive organ hangs outside of the body, even when the snake isn’t trying to reproduce. A prolapsed hemipene can get damaged, infected, and necrotized just like a prolapsed cloaca. Prolapse can affect only one or both hemipenes.
This type of prolapse happens due to calcium deficiency, constipation, straining, or trauma from improper probing.
Proper diet and hydration are equally important for male snakes! Solving underlying constipation and malnutrition can sometimes reverse mild cases of prolapse.
You should consult a reptile veterinarian nonetheless. Most hemipene prolapses require surgery and sometimes amputation of the affected organ.
Since a male snake has two hemipenes, it will still be able to reproduce if only one organ is amputated. A male snake can also live with no hemipenes, although it wouldn’t be able to breed anymore.
Infertile eggs are also known as “slugs.” They contain no snake embryo, only disappointment! Sadly, this happens even to the most experienced snake breeders. Sometimes, despite your best efforts, the eggs just fail to fertilize.
This can happen if the snakes are too old, or not properly stimulated to increase reproductive hormone levels.
If you breed the same male snake with multiple females, sometimes the male runs out of viable sperm to fertilize all the eggs. Unfortunately, the female snake still puts a lot of energy into producing these infertile eggs.
Sometimes, the entire clutch might be infertile. In other cases, there might be a few viable eggs for you to pick out. If unsure, try the candling method to tell them apart.
Shine a white light through the egg— if you see a reddish color, thin veins, or a small dark spot, the egg is fertile. Unfertilized eggs are blank and yellowish.
There’s no surefire way to guarantee egg fertilization. The best you can do is provide your snakes with an optimal diet, humidity, and temperature for optimal health and stimulation.
This includes both the brumation and breeding stages of their reproductive cycle.
Perfectly fertile and healthy eggs can just die spontaneously. And when this happens, the eggs change color to a yellowish shade. The shell might cave in, and start growing fuzzy white or dark mold.
When this happens, there’s nothing you can do to undo the damage. The only option is to remove the rotting eggs, as the disease can spread to healthy embryos.
Eggs typically start rotting in improper environments. Stale air, low temperature, and excessive humidity are all culprits.
Low temperature, poor air circulation, and excessive moisture uptake can stunt or kill embryos. To prevent rotting, remember to maintain a temperature of 78-84°F.
The relative humidity should be 75-85%. If the eggs look deflated, the humidity is too low. Damp shells indicate the humidity is too high.
Also, don’t forget the substrate— it should be moist, not saturated with water. Finally, don’t forget aeration. You’re most likely going to keep the snake eggs in a small plastic container.
Well, puncture some holes on the sides to allow air circulation. Otherwise, you’re more likely to get mold growing on the substrate and eggs.
Eggs not hatching
The eggs should be ready to hatch after 55-60 days (sometimes more, depending on the species). Yet, in some cases, the eggs won’t hatch, or the baby snakes die during hatching. There can be multiple underlying reasons for this. The first reason could be genetics.
Some baby snakes are too weak to come out of their shell on their own. Some snakes lack the egg tooth to crack the shell. The second possible reason could be the shell itself.
Sometimes, the shells become too thick and rigid due to high calcium and/or low humidity. You can help the baby snake by cutting the shell.
Finally, the eggs will sometimes fail to hatch due to turning and positioning. It’s very important not to turn the eggs throughout the incubation process. Some herpetologists mark the up-facing side of the egg with a pen for this reason.
If you turn the egg, you risk leaving the embryo facing down. There’s also the potential for the umbilical cord to wrap around the hatchling. In both cases, the baby snake might not be able to hatch.
Remember— the eggs must sit in the same position throughout the incubation period.
The hatchling should also lie face-up! Shine a light through the egg and mark the side where the embryo’s face is pointing.
You should simulate natural seasonal shifts to induce brumation and breeding in snakes. In the wild, snake breeding season starts in spring.
The rising temperatures, daylight hours, and food availability enable the snakes to come out of brumation and reproduce.
Maintaining optimal environmental parameters is also important for successful egg incubation. Snake eggs are highly sensitive to temperature and humidity fluctuations, which can kill embryos and cause molding.