Edward Bagnall Poulton in the context of "Sympatric speciation"

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.

The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, wherein species with strong defences evolve to resemble one another. By mimicking similarly coloured species the warning signal to predators is shared, causing the predators to learn more quickly at less cost.

Self-decoration camouflage is a method of camouflage in which animals or soldiers select materials, sometimes living, from the environment and attach these to themselves for concealment.

The method was described in 1889 by William Bateson, who observed Stenorhynchus decorator crabs. It was classified as "adventitious protection" by Edward Bagnall Poulton in 1890, and as "adventitious concealing coloration" or "adventitious resemblance" by Hugh Bamford Cott in 1940, who compared it to the way Australian aborigines stalked waterfowl, covering their faces with water lily leaves.