Why, after my dog kills something, (grasshopper, worm… Ect) does he roll himself all in it?
Dogs communicate with other dogs by smell, as well as body language. They can convey what’s currently going on by body language (and even short-term future plans, like I’ll go over there by the tree and you go over there by the rocks and we’ll flush out that rabbit). But for conveying past things, they use smell. Which we find icky when they’re trying to figure out what each other had for dinner last night. So to tell other dogs “Behold! I am a mighty hunter!” they will roll in their conquests. Even if it’s a worm. In ages past, they might have been bedecked in moose meat. They’ll also do this to get their “pack’s” smell on themselves, as a badge of where they belong. Unfortunately modern dogs’ packs often have stinky feet and other origins of stink.
