Projectile use by living systems

Although projectiles are commonly used in human conflict, projectile use by animals other than humans is relatively rare.

Most projectiles used by animals are liquids. Among invertebrates there are a number of examples. Velvet worms can fire a sticky fluid which they use to trap their prey. The fluid is fired from glands on the sides of their head. The spitting spiders Scytodes can spit a venomous and sticky fluid that traps its victims and also poisons them. The bombardier beetle is unusual by using a violent exothermic chemical reaction to launch a boiling noxious chemical spray in a rapid burst of pulses from special glands in its abdomen, accompanied with a popping sound. The Anthia (oogpister beetle) will fire formic acid at attackers, probably extracting the formic acid from the ants that it eats. The devil-rider stick insects (Anisomorpha) can fire terpenes from glands on the metathorax that can cause an intense burning irritation of the eyes and mouth of potential predators. Wood ants will spray acid at attackers. A type of planthopper of Madagascar is able to flick small balls of honeydew, this attracts day geckos that feed on the honeydew and whose presence may deter predators from approaching the sap-sucking insect.Termites of the North American termite subfamily Nasutitermitinae can project a sticky fluid from a nozzle on their heads. They can use this fontanellar gun accurately, over a range of many centimeters, even though the termite is blind, possibly using auditory or olfactory cues instead.

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