A stinger or sting[1] 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.[2]
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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.
Stings are usually located at the rear of the animal. Animals with stings include bees, wasps (including hornets) and scorpions.[3] Ants have venom glands but no stinger; instead, they eject the venom forcibly.[3]
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.[3] 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 by a relatively large animal; bees can sting other bees (in inter-colony raids) 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 only exceptions (yellowjacket wasps and the Mexican honey wasp) have barbs so small that they do not cause the sting apparatus to pull free, so they may sting more than once without harm to themselves.
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.
The term sting was historically often used for the fang (a modified tooth) of a snake,[4] although this usage is uncommon today; snakes are said, correctly, to bite, not sting.
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.[5]