Baby leopard geckos are born with dark bands that eventually transition into spots. ©Cathy Keifer/Shutterstock.com Many animals have two pairs of sex chromosomes: XX for females and XY for males.

Gargoyle geckos are native to New Caledonia, a French territory east of Australia. They're small, often colorful lizards that are easy to care for and have become more popular to keep as pets. Keep ...