kleptoparasite - an organism that gets its food by stealing it from other nearby organisms.

Commonly, a classification of spider behavior where larger spiders will often travel to nearby webs of smaller spiders of the same species and take captured prey.

Other interesting forms of kleptoparasitism occur in nature. Certain species of flies are attracted to the smell of Pentatomidae (stink bugs) and Coreidae (squash bugs) when they are being eaten in a spider's nest. They will then share in the meal with the spider. The captured stink bugs will eject a defensive spray on the spider. This spray will then attract the flies, which are now safe from the defensive chemicals.

Similar behavior is observed with many sea birds. The Roseate Terns found on the eastern coast of the United States will habitually steal fish from other nearby terns. The terns engage in all manner of attack incuding aerial piracy, ground based direct attacks and deceptive behavior, with the method of attack being specific to certain individuals. Kleptoparasites tended to obtain prey significantly more often than honest predators. Most kleptoparasitic terns were females, suggesting this behavior is encouraged by the need to forage for hatchlings in the breeding colony. This behavior is usually only limited to a small number of individuals in a breeding colony.

Maybe there is an evolutionary predisposition for bullies to steal your lunch outside of school?


Chemical Attraction of Kleptoparasitic flies to Heteropteran insects caught by Orb-Weaving Spiders. T Eisner, M Eisner and M Deyrup. PNAS 88, 8194 (1991).

Individual foraging strategies of kleptoparasitic Roseate Terns. Shealer, DA. and J. A. Spendelow. (2002) Waterbirds 25(4)436-441.