The cat snake is a type of tree snake with cat-like, vertical-slit pupils. There are numerous species of cat snake, indigenous to all continents. These nocturnal snakes are venomous, but the venom is normally too weak to harm humans. The various species of cat snake typically feed upon lizards, frogs, toads, small mammals, birds, and eggs.
Species of cat-eyed snakes can be found all over the world. Cat snakes of the genus Boiga, native to Asia, Africa, and Australia, can reach lengths of 1.6 to 9 feet (0.5 to 2.8 meters). Cat-eyed snakes of the African genus Dipsadoboa may reach lengths of 1.6 to 4.5 feet (0.5 to 1.4 meters). Species of the genus Telescopus, often found in Europe, may be 1.6 to 4 feet (0.5 to 1.3 meters) long. New world cat-eyed snakes of the genus Leptodeira are generally smaller, reaching average lengths of 1.6 to 2.6 feet (0.5 to 0.8 meters).
The varies species of cat-eyed snake often have very different markings. Asian cat snakes may have gold bands or yellow bars, while new world species often have indistinct dark blotches set against a lighter background. All cat snakes, however, are fairly slim. Their heads are usually triangular and often wider than their bodies.
All species of cat snake normally share the vertically-slit, cat-like pupils that give them their common name. These snakes are usually nocturnal, and do not generally become active until dusk. While the pupils of cat-eyed snakes may appear slit-like during daylight hours, they often widen and become rounder once night falls. Widening of the pupils improves the cat snake's night vision, by allowing more light into the eye. Cat snakes typically spend their days curled amongst the leafy branches of trees or bushes.
While female cat snakes can lay anywhere from three to 15 eggs per clutch, depending on their species, most cat snakes lay an average of seven eggs per clutch. They typically feed on small reptiles and amphibians, though they have also been known to hunt small mammals, including mice. Cat snakes may also feed on the eggs of birds and reptiles.
While most species of cat snake do possess venom, that venom is considered largely harmless to humans. The venom of these rear-fanged snakes is, however, usually strong enough to paralyze prey animals.