Most projectiles used by terrestrial animals are liquids. Among invertebrates there are a number of examples. Velvet worms can squirt out an slimy adhesive fluid from glands on the sides of their head, and use it to trap their prey. The spitting spiders Scytodes can spit a venomous 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 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.
A number of vertebrates also use liquid projectiles. The archerfish will squirt water from its mouth to dislodge invertebrates from overhanging branches. Some diptodactyline geckos can fire a black or pale yellow sticky fluid out of glands in their tail for a distance of about a meter, and with good aim. This fluid has a musky unpleasant odour and although it is not toxic it may discourage predators, in particular the big arthropods that prey on these geckos. The spitting cobra can squirt venom from forward-facing holes in its fangs. It aims for its victim's eyes, spitting up to 1.5 m. The venom may cause blindness. The Mangshan pitviper is also reported to spit venom.