A chemical substance or a blend of substances, usually a glandular secretion, which is used in communication within a species.

One individual releases the material as a signal and another responds after tasting or smelling it.

Primer pheromones alter the physiology of individuals and prepare them for new behavioral repertories. Releaser pheromones evoke responses directly.

A chemical substance exchanged among members of the same species that induces a state of alertness or alarm in the face of a common threat.

A pheromone with an active space restricted so close to the body of the sending organism that direct contact, or something approaching it, must be made with the body in order to perceive the pheromone.

A substance deposited on or around the nest that is colony specific or species specific and aids in the exclusion of alien colonies.

A substance laid down in the form of a trail by one animal and followed by another member of the same species.