Amouse runs for cover in the presence of a cat. the cat is an example of a(n stimulus.

The cat is an example of an external stimulus because an external stimulus is best explained on what is happening outside or in the environment. While the mouse who runs is an example of internal stimulus because the reason he felt the need to run was because of the cat which explains that it is internal because the mouse had experience emotions and the cat as external because the reason why the mouse felt the need to run was because he sense the environment of which he found the cat.