It occurs in many mammals; a prominent example is porcupines,[7] which raise their quills when threatened, or sea otters when they encounter sharks or other predators.

When these muscles contract, they increase the trapping of air on the surface of the skin and in turn, causes thermoregulation to the body.

Goose bumps can also be a response to anger or fear: the erect hairs make the animal appear larger, in order to intimidate enemies.

This can be observed in the intimidation displays of chimpanzees,[11] some New World monkeys like the cotton-top tamarin,[12] in stressed mice[13] and rats, and in frightened cats.

In humans, goose bumps can even extend to piloerection as a reaction to hearing nails scratch on a chalkboard, or feeling or remembering strong and positive emotions (e.g., after winning a sports event), or while watching a horror film.

Goose bumps are accompanied by a specific physiological response pattern that is thought to indicate the emotional state of being moved.

[15] In humans, goose bumps occur everywhere on the body, including the legs, neck, and other areas of the skin that have hair.

[16] Piloerection is also a classic symptom of some diseases, such as temporal lobe epilepsy, some brain tumors, and autonomic hyperreflexia.

Most research using musical stimuli has focused on self-reported "chills" which is a subjective experience, unlike piloerection which is an objectively quantifiable physiological reaction.

[25] It is not clear why the particular fowl, goose, was chosen in English (and German, Greek, Icelandic, Italian, Swedish, Danish, Norwegian, Polish and Czech)[26] as most other birds share this same anatomical feature.

For example, the hen or chicken is used in Vietnamese, Korean, Japanese, Cantonese, Finnish, Dutch, Luxembourgish, French, Spanish, Portuguese, Romanian, and Galician; Irish uses both;[citation needed] Hebrew, the duck; the ants (referred to as "murashki", alluding to the feeling of ants crawling on one's skin) in Ukrainian and Russian;[26] and a variety of synonyms in Mandarin.