For instance, light stimulation, heat stimulation, chemical stimulation, sound stimulation, etc. -The stimulus that comes from within an organism is the internal stimulus. Humor stimuli and neural stimuli etc (release of hormones such as thyroxine).
The jellyfish move between the twilight zone and the sunlight zone. They do so to be able to feed on the small photosynthesizing organisms at the upper surface of the ocean.
