A stinger or sting is a sharp organ found in various animals (typically arthropods) that delivers venom (usually piercing the skin of another animal). A true sting differs from other piercing structures in that it pierces by its own action and injects venom, as opposed to teeth, which pierce by the force of opposing jaws. Stinging hairs which actively inject venom on plants such as nettles are also known as stings, but not stingers.
The main type of construction of stings is a sharp organ of offense or defense, especially when connected with a venom gland, and adapted to inflict a wound by piercing; as the caudal sting of a scorpion. The wasp has a very painful sting, and will sting if it feels threatened.
Unlike most other stings, honey bee workers' stings (a modified ovipositor as in other stinging Hymenoptera) are strongly barbed, and lodge in the flesh of mammals upon use, tearing free from the honey bee's body, leading to the bee's death within minutes. The sting has its own ganglion and it continues to saw into the target's flesh and release venom for several minutes. This trait is of obvious disadvantage to the individual, but protects the colony, comprising many sterile workers who are all sisters, from attacks by large animals; the shared genes of the colony are more likely to be passed on if it is defended vigorously. The barbs ensure that a honey bee's attack is only suicidal if the attacker is a relatively large animal; bees can sting other insects repeatedly and without dying. The sting of nearly all other bees and other stinged organisms is not barbed and can be used to sting mammals repeatedly; the barbs on the stingers of yellowjacket wasps and the Mexican honey wasp) are so small that they do not cause the sting apparatus to pull free.
Other animals 
Organs that perform similar functions in non-arthropods are often referred to as "stings", although they are all technically considered to be something else (e.g., a venomous barb). These include the modified dermal denticle of the stingray, the venomous spurs on the hind legs of the male platypus, and the cnidocyte tentacles of the jellyfish.
In plants, the term "sting" is normally used as a verb, but occasionally used as a noun refer to urticating hairs; sharp-pointed hollow hairs seated on a gland which secretes an acrid fluid, as in nettles. The points of these hairs are brittle and break off easily, leaving a sharp point like a hypodermic needle, through which the fluid is injected.
See also 
- Oxford English Dictionary 2nd ed. has entry for sting but not stinger with this meaning; stinger is listed in a 1993 draft addition as a US synonym for sting (noun), with a first reference in 1895
- Oxford English dictionary, 2nd ed., sting n2, 3
- Thomas Eisner, Maria Eisner, Melody Siegler (2005). Secret Weapons: Defenses of Insects, Spiders, Scorpions, and other Many-legged Creatures. Harvard University Press. ISBN 978-0-674-01882-2.
- Oxford English Dictionary, 2nd ed. "Sting ... Applied also to the fang or venom-tooth (and erroneously to the forked tongue) of a poisonous serpent."
- Nicholas Stephens (2006). Plant Cells and Tissues. Infobase Publishing. p. 102. ISBN 978-0-7910-8560-8.
- Media related to Stingers at Wikimedia Commons