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 and that there may be significant variation in the selection pressure upon various snake venoms. Snakes use their venom to kill or subdue prey, as well as for other diet-related functions, such as digestion. Current scientific theory suggests that snake venom is not used for defense or for competition between members of the same species, unlike in other taxa. Thus adaptive evolution in snake venom has resulted in several adaptations with respect to these diet-related functions that increase the fitness of the snakes that carry them. Venom that is toxic only to a certain taxon, or strongly toxic only to