Male African fat-tailed geckos have broader heads and wider tail bases than females. Additionally, males have many obvious pores located on the underside of their legs. Some clues that can help indicate an African fat-tailed gecko’s gender include social interactions and egg deposition. Any gecko that deposits eggs is a female, and usually, those that fight with each other are males.
The swelling at the base of a male’s tail is created by his reproductive organs, called hemipenes. Males hold their hemipenes inverted, inside the base of their tails. When breeding, they avert one of the hemipenes and insert it into the female’s cloaca. African fat-tailed geckos can reach maturity when they are as young as 7 months of age although most take longer than this.
The gender of African fat-tailed geckos is determined by the temperature at which the eggs are incubated. Eggs kept between 83 and 85 degrees Fahrenheit usually become female, while those incubated at 88 to 89 degrees Fahrenheit become males. Eggs incubated at intermediate temperatures may become either sex.
African fat-tailed geckos are nocturnal predators of insects, arachnids and small lizards. If grasped by a predator, their tails may break off, allowing the lizard to escape. Usually, the tail regenerates.