When a cat or other certain mammals opens there mouth to use the Jacobsen's Organ to get a scent, also known as mouth-smelling.
Flehmen response
If it's a stallion, this is known as the "flehmen response" where he lifts his head up and curls his lip back to let the urine that the stallion "drank" of the mare to test for pheromones to see if she is ready to breed or not.
Flehmen response.
Trying to smell something
Wild horses mate in the same way as domestic horses. A mare that is in heat will urinate and present herself to the stallion. The stallion will sniff the urine and then the mare, typically displaying the flehmen response. So long as the mare is receptive the stallion will then mount her and breed with her.
Flehmen action is horses.
Geotropic response is response toward gravity.
A constructive response is a response that extends your answer and extends it.
A positive response is when a response happens to a stimuli, and this response causes more of the stimuli to happen. A negative response is when a response happens because of a stimuli, and the response stops the continuation of the stimuli.
response to water: hydrotropism, response to light: phototropism, response to chemicals: chemotropism, response to gravity: geotropism, response to touch: thigmatropism
Phototropism is the response to light. Geotropism is the response to gravity. Chemotropism is the response to particular substances. Hydrotropism is the response to water. Thigmotropism is the response to mechanical stimulation. Traumatotropism is the response to wound lesion. Galvanotropism is the response to electric current.
They are the same thing. The transient response is also known as the natural response.