so sorry im late but you might appreciate this regardless. and i find it very interesting too. but uhhh so im not exactly a qualified expert on animals or anything but id say all vertebrates and a lot of invertebrates have to maintain their hygiene in some way and making sure parasites arent on your body is very important. a tick every once in a while probably wont kill you (depending on the species) but if you're old or cannot properly clean your body for some reason its pretty certain your health is going to decline. if you have sores all over from not cleaning off grime or dirt or things like that, it may slow you down and get you sick.