Viperidae

Viperidae is a family of venomous snakes comprising two major subfamilies: Viperinae (true vipers) and Crotalinae (pit vipers). Members are typically stout-bodied with a broad, triangular head and long, hinged fangs (solenoglyphous) that can be erected for envenomation. They possess venom glands and, in pit vipers, heat-sensing pits between the eyes and nostrils that help detect warm-blooded prey.

Geographic range is broad, spanning Europe, Asia, Africa, and the Americas. They inhabit a variety of environments, including deserts, grasslands, forests, and mountainous regions. They are absent from Australia. They generally require warm climates and adequate prey.

Venom is primarily used for prey immobilization and digestion and is a major diagnostic feature; it is typically hemotoxic in many species, causing tissue damage, swelling, and coagulopathy, though venom composition varies widely among genera. Pit vipers tend to have venoms with proteolytic activity; some species have neurotoxic components. Envenomation risk to humans varies by species and region.

Life history: breeding varies; some species lay eggs (oviparous) while many pit vipers are viviparous (giving birth to live young). Offspring may be independent soon after birth. Diet consists mainly of small vertebrates such as rodents, birds, lizards, and amphibians. Behavior ranges from ambush predation to active hunting.

Taxonomy and diversity: Viperidae comprises roughly 30 genera and over 300 species, including Vipera, Cerastes, Echis, Bothrops, and Crotalus. They have ecological and medical significance; venom is the basis of antivenom production and medical research. Conservation concerns include habitat loss and collection of wild specimens.