Sexing Snakes Takes a Bit of Experience

Sometimes owners are curious if their snake is a male or female, but telling the difference is not a simple matter as male and female snakes look similar externally. However, with a bit of experience there are ways to tell, but these methods should be done by experienced keepers only. If you are a beginner and want to know the sex of your snake, please find an experienced keeper or vet to demonstrate for you, as the methods carry a risk of injury if done incorrectly.

Relevant Male Snake Anatomy:
Male snakes have a pair of hemipenes (sex organs) that normally sit (inverted) inside the snake from the cloaca down along the tail on either side of the snake's midline.

Visual Clues:
Since the sex organs are held internally, sexing visually is difficult, but there are visible clues. Because of the presence of the hemipenes, these visual clues relate to the shape and lenght of the tail:

* Male: tail thicker and longer than in females, and also tapers less evenly to the tip (thicker for a bit then suddenly thinning).
* Females: tail thinner and shorter than in males, and tapers smoothly, evenly and more quickly.

While the differences can be fairly notable when comparing snakes, it is more difficult if you don't have males and females side by side.

Probing:
Probing a snake involves inserting a thin metal rod (probe) into the vent or cloaca. The probe can be inserted further in males due to the presence of the spaces in which the hemipenes sit. A visual demonstration of the method is shown nicely at PetClubUK. This method is best left to the pros because inserting the probe incorrectly can badly injure the snake.

Popping:
In very young snakes, the hemipenes can often be visualized with a fairly simple maneuver called popping. A visual demonstration of popping can also be found at PetClubUK. It is recommended that you do not try this yourself either, though; if done incorrectly, the snake could be injured (or at best you might just get the sex wrong).

The correct identification of the sex of your snakes will play a key role if you wish to breed them. An experienced keeper will have more of an idea on what exactly to look for when determining the sex, however with the help of photographs I aim to give you a good idea on how to do this yourself.
Visual Identification

The first method is to visually see a difference in tail size and structure. Males have two hemipenes which are stored next to each other at the base of the tail. Each hemipene is tucked into its own 'pocket'. The effect of this is quite simple, it makes the tail appear fatter for a longer distance, generally making the overall tail length longer also. A female's tail narrows right from the base, making it almost 'carrot' shaped. The exact shape and length varies from species to species, but generally, the male has a longer tail.

Some species of snake are even easier to identify the sex. In some boas and pythons, males have prominent 'spurs' either side of their cloaca. This however, is not a guaranteed method in many species, as females too have spurs.
Probing

The second method is by use of a probe. A small, rounded metal rod can be inserted into the tail through the cloaca into the two 'pockets' either side of the base of the tail. The probe will penetrate farther into the male, whereas the female will only probe just a few scale lengths. This method should be carried out only by experienced keepers; it is a dangerous task if wrongly executed. Minimal force is needed for the probe to penetrate, yet it is a known mistake for people to apply too much pressure, resulting in the rupture of a female's scent glands. A lubricant must be used on the probe, Vaseline or KY Jelly are common substances to be used in this manner.

Popping

Popping a juvenile corn snake.The third method can be used on juvenile snakes. It is referred to as 'popping', which involves manually manipulating the hemipenes out of the male snake, while a female will slightly evert her scent glands. This method works better with younger snakes, directly after hatching is the time to obtain best results. At this age, the snake has not developed much muscle tone, making it relatively easy to force the hemipenes from the pockets.

Right Picture: Author 'popping' a male juvenile corn snake. The hemipenes are clearly visible.

I will explain how to do this if you are right handed like me. With your left hand, hold the body of the snake upside down in such a manner that the cloaca is held above the level of the rest of the body. With your right hand, pull the tail downwards slightly, and have your thumb resting approximately 2cm away from the cloaca. Gently roll and push your thumb down and across towards the cloaca, while at the same time bringing the tail upwards. This whole process sounds very complicated on paper, but I assure you it's easy once you get the hang of it. I highly recommend you to be taught this method by an experienced keeper before giving it a go yourself.

By Chris Jones
Director of PetClub UK Ltd.