Chemical signals released by an animal that communicate information and affect the behavior of other animals of the same species are called:

• A. Pheromones
• B. Neurotransmitters
• C. Hormones
• D. Neuromodulators

Answer: (A)

Pheromones are chemical signals released by one animal that influence the behavior of other animals of the same species. They travel outside the body and are detected by receptors in others, triggering specific behavioral or physiological responses that help with social communication—such as marking territory, signaling mating readiness, or warning of danger. This is different from neurotransmitters, which carry signals between neurons within the same organism and across synapses; hormones, released into the bloodstream, regulate physiology and behavior more globally but not as direct, immediate social signals to other individuals; and neuromodulators, while they affect brain activity, operate within the nervous system rather than serving as external signals to other animals.