The Family Boidae comprises a group of nonvenomous snakes commonly known as boas, found in the Americas, Africa, Europe, and some Pacific islands. Boids are constrictors, killing prey by coiling around and suffocating it rather than using venom. They typically have stout bodies, strong muscles, and heat-sensing pits in some species to detect warm-blooded prey. Members of this family range from moderate-sized snakes to some of the largest in the world, such as the green anaconda (Eunectes murinus). Boidae are ovoviviparous or viviparous, giving birth to live young, and they play an important role in controlling populations of mammals, birds, and other reptiles in their ecosystems.