Prey detection

Predators are in an evolutionary arms race with their prey, for which advantageous mutations are constantly preserved by natural selection.

Adaptations of prey that allow them to avoid predators are widespread, those that make them hard to find being collectively known as crypsis.

Crypsis may involve temporal evasion such as nocturnality, behavioral methods such as hiding, and non-behavioral adaptations such as camouflage.

Predators need not locate their host directly: Kestrels, for instance, are able to detect the faeces and urine of their prey (which reflect ultraviolet), allowing them to identify areas where there are large numbers of voles, for example.

Aposematic plants and animals may have conspicuous coloration such that potential consumers such as a herbivore will avoid eating them based on unpleasant past experiences.

It may also strike a non-vital organ: some species have deceptive appearances such that one part of their body resembles another, such as insects with false heads.

Prey have adaptations such as cryptic coloration in this Alaskan hare which help them avoid predators .
Experiments on blue jays suggest they form a search image for certain prey.
This ladybeetle ( Calvia decemguttata ) is easily spotted, but its conspicuous colors are a sign of its unpalatability , with which experienced predators would probably be familiar.