Boas belong to the Boidae family, which comprises pythons and boas of various shapes and sizes. Unlike other snakes, boas have two lungs, and they have rudimentary legs, which indicate their distant kinship to lizards. These snakes kill prey by coiling around the victim and constricting it until it suffocates. These snakes can be terrestrial, arboreal or burrowing. Boas are non-venomous.