Venom organ failure. Many caterpillars have defensive venom glands associated with specialized bristles on the body, known as urticating hairs, which can be lethal to humans (e.g., that of the "Lonomia" moth), although the venom's strength varies depending on the species. Bees synthesize and employ an acidic venom (apitoxin) to cause pain in those that they sting to defend their hives and food stores, whereas wasps use a chemically different alkaline venom designed to paralyze prey, so it can be stored alive in the food chambers of their young. The use of venom is much more widespread than just these examples.
Evolution of snake venom highly venomous caenophidian snakes (also referred to as "colubroidian snakes"), thus suggesting that most venom evolution took place after this lineage diverged from other snakes. The primary mechanism for the diversification of venom is thought to be the duplication of gene coding for other tissues, followed by their expression in the venom glands. The proteins then evolved into various venom proteins through natural selection. This process, known as the birth-and-death model, is responsible for several of the protein recruitment events in snake venom. These duplications occurred in a variety of tissue types with a number of ancestral functions. Notable examples