What term refers to chemical signals that help identify individuals of the same species?

The term that refers to chemical signals used to identify individuals of the same species is pheromones. Pheromones are specific chemical substances released by an organism into the environment that can affect the behavior or physiology of other members of the same species. They are particularly important in communication, mating, and social organization among many animal species.

For example, many insects use pheromones to attract mates, mark territory, or signal alarm to others in their colony. The unique 'signature' of pheromones allows individuals to recognize each other and engage in appropriate social behaviors, making them crucial for survival and reproduction within species.

In contrast, hormones are internal chemical messengers produced by glands that regulate bodily functions and behavior but do not primarily serve to identify individuals. Signals, while they can encompass various forms of communication, generally do not specify the chemical nature that pheromones do. Allomones, on the other hand, are chemicals that benefit the sender and may affect different species rather than serve the purpose of species identification.