The Saw-Scaled or Carpet Viper (Echis genus) are small, bad tempered, highly venomous snakes found north of the equator in Africa. Adults vipers reach an average length of just 20-30 inches. Their venom is hemotoxic and very virulent. This means the venom causes spontaneous internal bleeding, sometimes days after the bite has occurred. The Saw-Scaled viper is named for the sound it makes as its scales rub together producing a warning sound similar to a "sizzle". These venomous vipers are active after dark and that's when most of their victims are bitten.