Vipers are mostly more or less thick -bodies and short tailed, the head being entirely covered above with small scales, except in a single species.
The most widely known species are the Russell’s viper of India, the cape viper of Southern Africa, the puff adder of dry areas of Africa and Arabia, and the gaboon viper of tropical Africa.
Russell’s vipers and puff adders hiss loudly by expelling air through their large nostrils, the saw scaled or carpet vipers produce a characteristic rasping sound by rubbing their coiled together.
There are two subgroups, the typical vipers (Viperinae) and the pit vipers (Crotalinae). The Crotalinae have a special sense organ, the pit organ, to detect their warm-blooded prey.
The pit vipers occur in all types of terrain and may be found in the trees or on the ground. The tree snakes are slender; the ground snakes are thicker and heavy - bodied.
Viper snake
