Irritating Sting Wards Off Predators

Biological Strategy

Slender wild nettle

AskNature Team

Image: Wikimedia Commons /

Protect From Animals

Animals–organisms that range from microscopic to larger than a bus–embody a wide variety of harms to living systems, including other animals. They threaten through predation, herbivory, defense, and parasitism, and they compete for resources such as water, nutrients, and space. Any given living organism commonly faces threats from a variety of animals, requiring strategies that effectively defend from each. Trout and other bony fish, for example, escape predators by having scales made of very thin, flake-like pieces of bone covered with slippery mucus. They also have behavioral strategies such as camouflage, fast swimming, and twisting and turning to achieve release from a predator’s grip.

Search this Function

Flowering Plants

Clade Angiosperms (“receptacle seed”): Dandelions, oaks, grasses, cacti, apples

With 416 families containing some 300,000 known species, angiosperms are the most diverse group of plants, and they can be found around the globe in a wide variety of habitats. They are characterized by seeds that grow enclosed in ovaries, which are enclosed in flowers. The floral organs then develop into fruits of myriad kinds and dimensions, from simple seed casings on maples to elaborate fleshy growths like papayas. The oldest flower known from fossils, Montsechia vidalii, appeared during the Jurassic Period 130 million years ago. They are the primary food source for herbivorous animals, which in turn makes them the indirect food source for carnivores as well.

Search this Living System

Nettles ward off predators via stinging hairs.

Image: Jerome ProhaskaBYJP / Wikipedia /

Normal and stinging hairs of a Urtica dioica

Image: Wikimedia Commons /

Netlle leaves

“Other plants defend themselves even more aggressively. They sting. The nettle’s sting is a modified hair. Its tip is a minute glassy needle which if given even the slightest touch, breaks off. The broken edges are so sharp that they can cut skin. At the same time a poison held in a small chamber at the bottom of the hair squirts into the wound. The poison [formic acid] causes us considerable pain.” (Attenborough 1995:64-65)