What type of chemical signals can influence animal emotions?

Pheromones are chemical signals that play a significant role in influencing the emotions and behaviors of animals, particularly in social and reproductive contexts. These chemicals are released into the environment and can evoke specific responses in other individuals of the same species through olfactory (smell) detection. For example, the detection of stress pheromones can signal danger or alert other animals to a potential threat, influencing their emotional state and behavior.

While hormones, enzymes, and neurotransmitters all have essential roles in biological processes and can affect mood and behavior, they typically operate within the body rather than serving as external signals between individuals. Hormones can influence an individual's internal state, while neuropeptides act at synapses affecting mood and cognition. Enzymes are primarily involved in biochemical reactions and do not serve as signaling molecules for emotional influences in the same way that pheromones do. Pheromones uniquely facilitate communication and emotional responses across individuals, underscoring their importance in social and behavioral interactions among animals.