What type of response is salivation when entering a kitchen with the smell of food?

Salivation when entering a kitchen with the smell of food is an unconditioned response. This response occurs naturally and automatically in reaction to an unconditioned stimulus, which, in this case, is the smell of food. When dogs encounter appetizing scents, their physiological reaction to produce saliva occurs without any prior learning or conditioning; they instinctively associate the smell with food and the expectation of eating, which is an innate behavior.

Conditioned responses, on the other hand, develop through learning and association, while secondary reinforcers are stimuli that gain their reinforcing properties through association with primary reinforcers, such as food. Excitement may be a general emotional state but does not accurately describe the physiological response of salivation specifically in reaction to food smells.