aposematism

thumb|upright=1.5 |The bright colours of this granular poison frog signal a warning to [[predators of its toxicity.]] thumb|upright=1.5 |The honey badger's [[reverse countershading makes it conspicuous, honestly signalling its ability to defend itself through its aggressive temperament and its sharp teeth and claws.]]

Aposematism is the advertising by an animal, whether terrestrial or marine, to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defenses that make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous coloration, sounds, odours, or other perceivable characteristics. Aposematic signals are beneficial for both predator and prey, because both avoid potential harm.