What are the three different types of stimuli?

The three different types of stimuli are physical, chemical, and biological stimuli. Physical stimuli include changes in the environment, such as light, sound, and temperature. Chemical stimuli involve the presence of specific molecules, like odors or taste substances, that can trigger sensory responses. Biological stimuli refer to living organisms or their activities, such as the presence of predators or mating calls that elicit reactions from other organisms.