Probing
Hands-on
Expert only
- Male
- Probe typically goes 8–10+ subcaudal scales.
- Female
- Probe typically stops at 2–4 subcaudal scales.
- Reliable from
- Any age; most reliable once past the first few sheds
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Reptile sexing guide
Pick a species to see every sexing method, what males and females look like, when each method becomes reliable, and how hard it is.
Probing and popping can seriously injure an animal if done wrong — including hemipenal damage and prolapse. Have an experienced keeper or reptile vet show you first, use proper lubricated probes, and never force anything. When in doubt, wait for the animal to grow or ask a vet.
Popping (hatchlings only)
Hands-on
Expert only
- Male
- Two red hemipenes evert with gentle pressure below the vent.
- Female
- No hemipenes; only small scent glands or nothing appears.
- Reliable from
- Hatchlings only, in the first days to weeks; unreliable and riskier after that
Cloacal spurs
Visual
Moderate
- Male
- Spurs are often larger and more hooked.
- Female
- Spurs are often smaller — but many females have large spurs too, so this is only a hint.
- Reliable from
- Adults; never use alone
Tail length and shape
Visual
Moderate
- Male
- Longer tail that stays thick after the vent, then tapers gradually.
- Female
- Shorter tail that narrows quickly right after the vent.
- Reliable from
- Easier on adults; compare siblings as juveniles
Diagrams are simplified cartoons to train your eye. Photograph your own animal and compare it side by side. For species where these methods are unreliable, a DNA test or a vet ultrasound gives a definite answer.