Lizards are reptiles. Lizards, commonly known as "four-legged snakes" or "aunt snakes", are distributed all over the world. It belongs to cold-blooded reptiles, with a wide variety, about 3000 species distributed on the earth, and more than 50 species are known in China. Most of them are distributed in the tropics and subtropics, and their living environments are diverse, mainly terrestrial, arboreal, semi-aquatic and digging holes in the soil. Most of them eat insects, and a few plants also eat insects at the same time. Lizards are oviparous, and a few are oviparous. Lizards and snakes are closely related, and they have many similarities. The whole body is covered with cutin scales derived from epidermis, and the anal orifice is transverse fissure. Males have a pair of connectors, both of which are oviparous (or some oviparous species), and the square bone can move.