Just wondering. :)
-
They have to be to survive. The deer that are just chillin' in the woods, not constantly scanning for predators are the ones that get eaten! It pays to constantly be on edge when your a herbivore with very little means of protection other than to run like hell.
-
they have a lot of predators (bears, wolves, cougars, etc.) so if they see another large creature approaching it that is not another deer they may just flee to avoid potential danger.
-
Because so many other things want to kill/eat them.
-
they are prey, it is a survival instinct.
-
watch bambi