In the winter many dogs grow a thick coat of fur. this is an example of?

This is an example of a response to stimuli.

This the example of response to stimulus.

When seasons change, so do an animal's hormones. These hormonal changes trigger shedding. When the weather grows colder, the hormonal changes causes the fur coat to grow thicker. This helps keep the animal warm during the frigid winter months.

synapse nervous system