For young specimen, the easiest and safest way to sex them is “popping”. Popping is the process everting the animal’s sexual organs to determine the sex. Male Royal Pythons have inverted hemipenes located below the cloaca inside the tail. When we “pop” a male, the hemipenes will be everted and indicate that it is in fact a male. Females do not possess this sexual organ so no hemipenes will be present when popping. Females posses a scent gland here, so when you pop them, no hemipenes will be everted, but you can generally see the scent gland. The scent gland is usually pink / white in colour with tiny red blood vessels.
Great care is needed when popping an animal as too much pressure, or pressure in the wrong place can damage your snake. It is always best to have an experienced breeder or reptile keeper show and teach you how to use this method before attempting this yourself.
The most effective way to sex a Royal Python is by probing. Probing isn’t an acceptable method for small snakes as their under-developed sexual organs can often be too fragile. Probing is best used on fully mature snakes. Probing is the process of inserting a small probe under the cloaca, and down into the sexual organ to determine the sex. The probe will travel further in a male as the probe is entering the inverted hemipene. The probe distance for a male is roughly between 9-15 subcaudal scales. Females probe much more shallow, usually the distance of 1-5 subcaudal scales.
Probing should never be attempted without the training from a well experienced breeder or reptile keeper. Too much pressure, the absence of lubricant or incorrect sized equipment can all be a potential harm to your animal.