Many boas and pythons possess spurs located on either side of the vent, and in many males, these spurs are larger. In general, the tail of male reptiles is proportionally longer than the female's. There are other ways to differentiate the sexes of reptiles, including ultrasound, surgical sexing and radiographs. For specific information, please consult your herp vet if you are unsure about the sex of your reptile. While it would seem that reproduction is a natural event, without correct circumstances, such as a balanced diet and a suitable environment for egg-laying, eggs may not develop normally or be laid in a timely manner.
Owners are often surprised to find that their single pet female lizard has developed eggs.
A healthy adult female does NOT need the presence of a male to become gravid. For fertilization, a male reptile inserts either one of his two hemipenes into the female's cloaca, or the single penis is inserted. Before actual copulation, the pair usually engages in some type of ritualized courtship. After copulation, sperm can be stored for up to six years, and this stored sperm can fertilize subsequent clutches without additional contact by a male. Using the green iguana as an example, even without a male present to fertilize eggs, a healthy adult female may begin developing eggs.