The largest family of snakes is the Colubridae, most of whose members are harmless to humans. The living lizards are placed in 16 families. The largest family of lizards in the Americas is the Iguanidae, which includes the anoles, iguanas, and basilisks. The monitor lizards, including the Komodo dragon, are in the family Varanidae. Among some species of reptiles, reproduction is preceded by courtship that involves visual and auditory displays.
Some male lizards expose brightly colored body parts, and the nocturnal geckos give mating calls.
Some aquatic turtles have courtship rituals in which the male vibrates his foreclaws against the female's head. Male snakes may rub their chins along the female as a prelude to mating. Reptile eggs have large yolks that provide nourishment to the embryo throughout its development and, in some species, for a short period after the young are born. After a reptile is born, its growth is rapid until it reaches maturity. Most reptiles grow for at least a year, and many turtles grow for several years before reaching maturity.