Final answer:
When chemical signals are exchanged between animals, it is known as chemical communication, which often involves the release of pheromones to trigger responses in other animals of the same species.
Step-by-step explanation:
When chemical signals are sent between two animals, chemical communication is being used. Chemical signals, often in the form of pheromones, are substances secreted by an organism to trigger a social response in members of the same species. An example includes the three-spined stickleback fish, where a visual signal is used for aggression in males and mating cues for females. However, the communication we're focusing on involves chemical messengers called ligands, which bind to specific receptors in target cells and exert their effects over varying distances, depending on the type of signaling—paracrine, endocrine, autocrine, or direct signaling across gap junctions.
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