The stories of huge boa constrictors (Boa constrictor) crushing people to death are gross exaggerations. The boa is only the world's fifth or sixth largest snake and, on average, only half the size of an anaconda. But, like the anaconda and python, the boa kills by wrapping its coils around the victim's chest and squeezing. As the unfortunate creature exhales, the snake tightens its grip until the prey can no longer breathe and is ready to be swallowed.
Bats make a favourite meal and the boa constrictor hangs from a branch near the entrance to a cave and catches the bat as it flies by. Under the snake's upper lip, heat sensors help it to locate warm-blooded mammals. Because of its penchant for rats, it is sometimes kept as a pet to control rodents.