Tree boas hang from sturdy branches and wait for small birds to fly by or small mammals to pass beneath them. The snake's eyes have vertical pupils. Just like small cats, this makes them better at sensing the movements of small prey in the gloom of the forest. Tree boas also have heat-sensitive pits on their snouts, which allow them to detect the body heat of prey moving near them. The snake waits, ready to pounce, with its upper body in an S-shape. When a prey animal comes close enough, the tree boa lunges forward and grabs it in its mouth. The snake's backward-curved teeth stop victims from struggling free.
During mating, the male entwines his tail with the female's. The female gives birth to between 3 and 15 young. The young snakes are red or orange for the first year of their lives.