Vipers (Viperidae) are a family of exclusively venomous snakes. They have a stocky body and a very short tail. Because of their large venom glands, most members have a broad, heart-shaped head. The elliptical pupil of their eye is vertical. They have a short upper jaw, on its front part there are two large, very sharp, backward-curving fangs.
The viper family occupies all continents with the exception of Australia and Antarctica, and they are also not found in the northern parts of Asia and North America, in the mountain ranges in western South America, Madagascar, Papua New Guinea and New Zealand. There are over 180 known species of this family, which are classified into 17 genera. In Slovenia, three species of this family live; of these, two are found in the Notranjska Regional Park.
