Toxungen

As one of three categories of biological toxins, toxungens can be distinguished from poisons, which are passively transferred via ingestion, inhalation, or absorption across the skin, and venoms, which are delivered through a wound generated by direct contact in the form of a bite, sting, or other such action.

Toxungens have evolved in a variety of animals, including flatworms,[4] insects,[5][6] arachnids,[7] cephalopods,[8] amphibians,[9] and reptiles.

[10] Toxungen use possibly also exists in birds, as a number of species deploy defensive secretions from their stomachs, uropygial glands, or cloacas, and some anoint themselves with heterogenously acquired chemicals from millipedes, caterpillars, beetles, plant materials, and even manufactured pesticides.

Skunks and several other members of Mephitidae and Mustelidae spray a noxious and potentially injurious secretion from their anal sac when threatened.

Snakes of the genus Rhabdophis sequester their nuchal gland toxins from their diet of toads and/or fireflies,[26][27] Blue-ringed octopuses (genus Hapalochlaeana) acquire tetrodotoxin, the highly toxic non-proteinaceous component of their salivary glands that can be ejected into the water to subdue nearby prey, via accumulation from food resources and/or symbiotic tetrodotoxin-producing bacteria.

Many hymenopterans possess a secretion used as a venom (injected for predation and/or defense) that can also be sprayed to communicate alarm among nestmates, to mark a trail used for food gathering, or to keep their brood free of parasites.