A pheromone is a scent given off by some animals. The scent causes a social response in members of the same species.
There are many types of pheromone, such as:
- Sex pheromones (to attract a partner): e.g. butterflies and moths
- Alarm pheromones (to warn the group): e.g. wasps
- Food trail pheromomes (to let others know what has been found): e.g. ants
- Territorial pheromones: e.g. cats and dogs
- Various 'short-term' pheromones cause a rapid but brief behaviour: e.g. releasing a cluster of nymphs, or positioning the body for sex.
All pheromones work by inherited instinct, not by learning. They occur in most animals, but are especially obvious in insects.