What is a pit viper? Do any live in North Carolina?
Five of North Carolina’s six venomous species are pit vipers. The distinguishing feature is the heat-sensing pit, or indentation, between the eye and nostril on each side of the head (lateral head figure, right). The pits face forward and are used to detect differences in temperature. The snakes’ “binocular” heat-sensing ability allows them to detect in total darkness the location and probably the size of warm-blooded animals. This faculty is primarily used to acquire food—just as snake venom is. However, it also can help snakes detect the presence of animals that might prey upon or otherwise harm them. All pit vipers have vertical, elliptical pupils, and most of the scales under the tail are in a single row, (tail figure, left) although these characteristics can be difficult to observe. The eastern coral snake is the one venomous species in North Carolina that isn’t a pit viper. It has many characteristics in common with the 31 nonvenomous snakes, which have round pupils, no pit and a
