Professional Herpetoculture for the Pet Trade

How To Breed Ball Pythons

Breeding Ball Pythons

One of the questions we get asked quite often is "How do I breed my Ball Python". This article will explain how we do it, using methods we've developed at VMS over the last twenty-plus years. Some articles may differ from the methodology presented here, and some may view it as overly simplified. Remember, Ball Pythons have been breeding in the wild for thousands of years without our help - they'll do it just fine in our cages, no need to make it harder than it is!

Do you really want to breed your Ball Python?

This seemingly simple question is often never considered by the novice. There are several reasons to consider NOT breeding your Ball Pythons!

First, do you have a market for the offspring once they have been produced? If you don't have a place to sell them, you can quickly tire of feeding all those little mouths and then cleaning up after all those little...well you get the idea.

Second, do you have adequate food supplies and caging for the offspring? A typical Ball Python clutch of six hatchlings will consume around six rat pups per week if all goes well. Some can be fussy and require live hopper mice, others want live rat pups, others will waste feeders by refusing for several days before accepting and then repeating that process. All of which can be inconvenient if you don't have a handy source and dependable source. That's a lot of mice and rats. So many in fact, that local pet shops frequently begin experiencing mouse 'shortages' caused by the increased demand during peak months.

Third, are you willing to risk the life of your Ball Python? Breeding snakes is not without risks. On very rare occasions, one snake may actually simply eat the other on introduction. Dystocia (commonly known as egg-binding) is fairly common and poses serious health risks that may require expensive veterinary services. More common is the incredible drain on body resources that egg production places on the female. If not in perfect health, a female can become severely weakened and may succumb to renal failure or disease. Speaking of disease, the simple act of introducing the two snakes together opens the door for pathogen transfer. It is not uncommon for snakes to carry substantial parasite and bacteria loads and appear perfectly healthy, even for years. Introducing such a snake to another may transfer pathogens the second snake is unable to combat; it may then sicken and die.

I'm not trying to tell you not to breed your Ball Pythons, just making sure you are aware of a few of the problems associated with it. If you still want to breed them, read on!

The Calender of Events

I'll try to present all of this information in the order it occurs, to enable the reader to grasp the entire cycle of events. Breeding Ball Pythons is not simply something you just do one day, it is an event which consumes an entire year. Ball Pythons spend their entire lives in the wild preparing for this one annual event - you should spend just as much time on it as they do! Please remember that these dates are not set in stone, variations in cage temperatures and other conditions may cause your results to vary. In fact, Ball Pythons are notorious for breeding pretty much whenever they feel like it, and you should always be mentally prepared for it to take place at any time. However, the overall sequence of events will remain unaltered and the vast majority of breedings will more or less follow the timing given here.

December, January, February

Our Ball Pythons are now undergoing what is often termed temperature 'cycling', which we begin around December 1st each year. Many keepers call this the breeding season, and in fact the snakes will copulate frequently during this period. Actually, they are in preparation for breeding, and while they mate readily - it seems to be the copulations which take place after spring warm-up that really seem to count.

Pay careful attention to them during this time. Most areas have much drier climates during the winter months and dehydration can be a problem. Make sure they have clean drinking water available at all times and check for 'dry shed' often. Many times, the snakes can be seen soaking in the water bowls when the climate is too dry. Many of our snakes will go off feed about this time, although it seems to us as though many females which go on to breed successfully later in the year will actually feed very aggressively during this period. But virtually all our males will simply stop at this time, often all will eat one week and then refuse the next week - it's that sudden!

We maintain our colonies at a temperature of 85-88 degrees Fahrenheit during the day throughout the 'cycling' period. At night, temperatures are allowed to drop to 73-75 degrees Fahrenheit and no substrate or 'belly' heat is provided at this time. We also greatly reduce the photoperiod, matching that occurring naturally outside our home. Temperatures are checked several times daily and the night-time temperature drop is controlled by a thermostat and enhanced by timing exhaust fans to pull hot air out of the room at dusk. It is also recommended that air circulation be provided by using a fan. You would be surprised at how warm one end of the room can be while the other gets too cold!

During the entire three month cycling period, we introduce females into each males enclosure regularly. Most are left with the males for two days and then replaced with a different female. Since our preferred male to female ratio is one-to-three, with a maximum of one-to-four, this means each female is with the male once every six or eight days in most cases.

We're still feeding all our pythons, although offering smaller meals than during warmer summer months. Usually, sometime during the cycling period, most if not all of our males will cease to feed as their interest in ripening nearby females seems to take precedence over all else. Remember that egg follicles are developing and spermatogenesis is occurring in the males as well. It's important to maintain good conditions during this time so that all goes smoothly or infertile eggs will surely be the result.

March, April, May, June, July

Oh boy, now the work really starts! We usually warm our snakes back up to normal maintenance temperatures at the beginning of March. Belly heat is again provided at this time. Introductions and copulations now seem to take on a more serious attitude, with virtually all males refusing to feed due to excessive interest in females. We are now feeding very heavily to all snakes that will accept food.

We usually introduce the female to the males' cage. You can do it the other way around, doesn't seem to matter, we just like to do it this way. If all is well, the male will show interest immediately, often pausing to smell the female as she glides by. Once he has determined that she is full of developing eggs, his interest will quickly grow and he will approach the female. Typical courtship involves lots of chin rubbing on the females back, followed by tactile alignment and spur scratching, then actual copulation.

It's important to determine if an actual copulation with intromission has taken place. Many males will simply rest with a female, positioned as if copulating, even so far as having the tail underneath. Novice breeders frequently assume the pair has bred, often leading to undesirable results when they then cease introductions.

Figure 1: a pair of copulating Ball Pythons

Here's a typical copulation scene, with the male  successfully copulating with the female (Fig. 1). You can see he has lifted her tail section a bit by forcing his tail under hers. Experienced males like this one, often place a body coil on top of the female just anterior to the vent, and the lifting action of his tail under hers will practically force the cloaca open.

If all goes well with this attempt, a closer look will reveal a successful copulation in progress. Below you can clearly see that this pair knows what they are doing and soon I'll be the proud daddy of a mixed clutch of Ivory, Yellow-Belly and Normal Ball Pythons (two Yellow-Belly Ball pythons are shown below).

We'll continue introducing the pair together for periods of a day or two at least once per week, until the female becomes visibly gravid. Once we see the snake is gravid, we may cease introducing the male to her, but only if we are absolutely certain.

Figure 2: close-up view of a pair of copulating Ball Pythons

One of the most common questions we get at VMS about breeding Ball Pythons, is how to tell when a Ball Python is gravid as opposed to ovulating. Usually, it's not too hard to tell once you've seen it, but I've always advised folks to simply continue introducing the pairs all the way to the end if they are not certain. Simply put, if a gravid snake gets placed with a male, so what? But if a female isn't been getting placed with a male at the right time, then you get infertile eggs. This is not rocket science. With some females, it can be difficult to determine, and we've had a few snakes lay eggs while still being introduced to the male.

Many breeders focus on trying to determine when the female ovulates. This is easily recognized once it's been seen a few times, but otherwise easy to miss. It simply resembles a huge meal, as if the female had just eaten the largest rat of her existence, but it only lasts a day or so, and we rarely catch it. The simple truth is, we're not too concerned about it. It's been our experience that if successful copulations have not already taken place prior to ovulation, then clutches consisting of mostly infertile eggs will result. So what are you watching for, the point at which it's too late? If we are uncertain of the status of the females egg development or follicle development, we'll simply continue introductions until she either lays eggs or all our other females have done so and we've grown certain this one will not for the year.

I suppose we could invest in an expensive ultrasound machine to help determine all of this, but simply giving the snakes every opportunity to reproduce seems simpler. We've seen several 'experts' utilizing ultrasound machines make judgmental errors in reading the results, so just follow this simple rule of thumb if you are uncertain: PUT THE SNAKES TOGETHER! They've been happily finding each other and breeding successfully in the wild for thousands of years without use of ultrasound machines or careful planning, they'll handle it by themselves as long as you give them the opportunity.

Many females will lay their eggs in the last two weeks of May, although a few will not lay until July. For reasons not understood, we tend to see these same two peak laying periods each year. Remember that Ball Pythons often fall off the planned schedule, and we've had clutches appear as early as April and as late as July. Determining whether a snake is gravid (carrying eggs) can be difficult, but here's a few tricks:

Figure 3: a gravid female Ball Python

The first clue is a general heaviness throughout the lower half of the snake. Often, this is most visible from above and many females begin to show a 'peaked' look along the spine. This is due to body fat reserves and muscle mass along the sides being used up to produce eggs, which ride lower in the body cavity. Here you can see a gravid Pastel Ball Python (Fig. 3), which laid her eggs about an hour after this photo was taken. Note the peaked look of the body, bulging lower sides, with the swelled area beginning just an inch or two above the vent. On white or albino snakes, you can even see the white coloration of the eggs through the body wall.

Sometimes, a gravid female will become restless, as if searching for a place to lay her eggs. Well, she is - so give her one! We use medium size Rubbermaid boxes which are filled half way with damp sphagnum moss. Try not to add too much water to the moss. It should be only lightly dampened. Moss that is too wet will quickly turn a very dark blackish brown in color. While we used to make fancy tops for access, we now simply use the box itself, and discard the lids.

Figure 4: a surprise clutch

I've mentioned several times that I've had females lay eggs while still with the male, during late introductions such as I previously described. Usually this gets me some weird looks and comments of disbelief. So here's a photo (Fig. 4) taken one morning of a female just finishing laying eggs (the last egg was still wet when I removed the clutch a few minutes after this photo was taken). If you look carefully, you can see she is wrapped around not only her clutch, but also her mate - a small male Mojave Ball.

You may also note that there is no lay box, as we often don't use them. I've gotten some comments about that as well, but let's save that discussion for another day! In most cases, I'd just recommend the use of a large enough box for the female to get inside, filled with lightly dampened sphagnum moss. Probably best to "do as I say, not as I do" on this one.

Figure 5: a Ghost Ball Python on eggs

If all has gone well and you've done as I said and not as I did, you should one day open the cage and see something like this Ghost Ball Python on her newly laid clutch inside the lay box (Fig. 5).

Carefully remove the female from the eggs, trying to keep them right side up. Many keepers will mark the tops of the eggs to help prevent accidentally inverting them. It may help to have an extra set of hands, as many females do not want to be pried away from the egg mass. I've had a few bite, but mostly they just can really hang on to the egg clutch! Now place your eggs in the incubator (which hopefully is already set up) and wait.

It is recommended that the female's cage be completely cleaned and sterilized at this time, and we also thoroughly hand wash the female in a mild soapy water before placing her back into the newly cleaned cage. This is done not to sanitize conditions, but rather to remove all traces of egg scent, allowing her to more quickly forget the now missing clutch of eggs and resume feeding. Failure to do so almost always results in a female attempting to incubate the water dish or a pile of bedding, and refusing to feed for weeks.

Much has been written about incubation, too much in fact. In truth, a healthy clutch will hatch in just about anything other than the glove compartment of your car. The only requirements are that humidity be held rather high and that temperatures stay within reason. We hatch all of our Ball Pythons at 88-92 degrees, but it can vary a bit. I've seen eggs hatch anywhere from 78 to over 90 degrees with no ill effects. During a spring power outage at our facility, our eggs cooled to 65 degrees for a period of at least twelve hours, and all hatched without problems. Stable temperatures are not as important as most breeders believe. In fact, recent research indicates that some variation in temperature may actually produce a more even sex ratio in the hatchlings and produce larger, stronger hatchlings.

Figure 6: Ball Python eggs incubating

We use plain old vermiculite as a media, mixed with water. It is available at garden centers. You do not need to get crazy over how much water! I've seen a gazillion ratios by weight and volume - ignore it all. Just add water until the vermiculite will pack into a 'snowball' and when squeezed very hard will barely yield a drop of water. We place the eggs in clear plastic shoeboxes or sometimes in Tupperware type containers, without ventilation holes of any kind. We simply open the containers for air exchange once a week as we check for any dead or rotting eggs. A healthy clutch of eggs set up properly should look something like this: (Fig 6.)

Notice all of the good eggs here are clean and white, the eggs are very full and smoothly rounded. Often such eggs will adhere in a clump. This is actually a terrible looking clutch, but was used here to illustrate that many eggs normally have discolored areas or water spots. You needn't worry about such minor imperfections in eggs, and all four of these hatched perfectly. The single egg at right is infertile, and such eggs will appear yellowish and often have a wet feel to them, not dry like the four eggs at left in this clutch. Often, infertile eggs will not adhere in clumps as do the healthy eggs. If you are not sure, set them up for incubation anyway and discard them as they begin to mold. Try to separate them from any good eggs, to prevent the mold from spreading. Usually, infertile eggs can be pulled from a clutch without much trouble - for some reason they seem less adherent than healthy eggs. Never try to separate healthy eggs, they will almost always tear. Stubborn infertile eggs can often be carefully 'sawed' away using waxed dental floss, an idea we got from Dave and Tracy Barker of VPI.

Many breeders state that you do not need to remove bad eggs, usually saying something along the lines of "good eggs have a natural fungus inhibitor and it is not necessary". While good eggs do have a certain natural immunity, bad eggs still smell and certainly foul the air the good eggs are 'breathing'. I have seen certain types of fungus develop and kill entire clutches, so why not just remove them?

One extra note here: Often a female will be seen carefully coiled around her clutch, but with a single egg or two off to the side, not coiled within. These eggs are called 'roll-outs' and in almost all cases fail to hatch, although they appear to be fine fertile eggs. However, you might as well set them up to incubate, just in case!

August, September, October, November

Most of our females have laid eggs by now, although there may still be a few 'gravid ones' around. Within a day or two after laying, most females will resume feeding if the above mentioned washing procedure has been done. Again, offer small meals, increasing the size and frequency until your female is feeding normally again. She should regain body weight quickly, and will usually shed her skin shortly after laying.

This is the real beginning of what I call 'the fattening'. During this period, Ball Pythons will consume an astonishing amount of food. While our males will be on a maintenance diet of perhaps one feeding each week, the females will be getting a small meal every three or four days! They've earned it, as most have produced fine clutches of eggs for us. If your snake has produced eggs earlier in the year, by all means start fattening her up earlier - don't wait!

Soon, many females will regain a nice plump appearance. It always amazes me how fast this can happen - provided the female was not severely stressed by overproduction. At this time, we'll evaluate each for weight gain and begin planning our potential pairings for next year's breeding season. Those that are not regaining weight well, are marked and carefully observed for any problems which may require veterinary attention.