Well, duh! But you would be surprised how many people don't seem to know that plants are alive, that they move, and that they respond to stimuli. The perceptual problem is simple, plants operate on a slower time scale and we either need to use technology, like time lapse photography, or a lot of patience to see what they do. A colleague has been using such films in teaching and generating curiosity about how plants do things, and he's posted them for your edification, amusement, and use! Pop over to Plants in Motion and have a good time.