In ecology, predation describes a biological interaction
where a predator feeds on its prey. Predators may or may not kill their prey
prior to feeding on them, but the act of predation often results in the death
of its prey and the eventual absorption of the prey's tissue through
consumption. Other categories of consumption are herb ivory and detritivory,
the consumption of dead organic material. All these consumption categories fall
under the rubric of consumer-resource systems. It can often be difficult to
separate various types of feeding behaviors.
For example, some parasitic species prey on a host organism
and then lay their eggs on it for their offspring to feed on it while it
continues to live or on its decaying corpse after it has died. The key
characteristic of predation however is the predator's direct impact on the prey
population. On the other hand, detritivores simply eat dead organic material
arising from the decay of dead individuals and have no direct impact on the
"donor" organism. Selective pressures imposed on one another often
leads to an evolutionary arms race between prey and predator, resulting in
various ant predator adaptations. Ways of classifying predation surveyed here
include grouping by trophic level or diet, by specialization, and by the nature
of the predator's interaction with prey.
