The difference between an external stimulus and an internal stimulus is that an external stimulus is a stimulus that comes from outside an organism. But an internal stumulus is a stimulus that comes from inside an organism. An example for an external stimulus can be that when you are cold, you put on a jacket. An example for an internal stimulus is that when you feel hungry, you eat food.
Rising CO2 levels.
when we touch a hot object we immediately (even without thinking) withdraw our hand. touching the hot object is the stimulus and withdrawing our hand is the response
External:temperature falls and you shiver. Homeostasis:get your body warm!😉
a example: A hot girl is so hot she wants to get in pool then she drinks water to get energy to get back in the pool and swim.