Hyenas don't have to protect themselves very often. They have no natural enemies and therefore do as they please. The only enemies they do have is Lions and not even a pack of female lions will take Hyenas on. The only time female Lions will attack Hyenas is if they have a male Lions as backing. Lions hate Hyenas so much that once they do kill a Hyena then they won't eat it no matter how hungry the Lions are, they will just destroy the Hyena. Hyenas got the strongest jaws of all animals and can crush bones like it is nothing. They are also very sneaky and before any of the wild cats realize what is happening then there they are a whole pack of Hyenas so rather risking getting injured the cats would leave their kill to the Hyenas. The only time a Hyena would run away is when a male Lion attacks it, because only a male Lion would dare to kill a Hyena. I had the, shall I say good or bad fortune of meeting a Hyena eye to eye in the wild one night, only thing I remembered was not to run because then they will kill you so instead we were looking each other in the eye for a few seconds and both of of turned around to opposite side and as soon as I was around the corner I ran like hell
By running in large packs.
Coyotes do not reveal the teeth closed, but will put up hair in order to increase the body. Predators attack, smelly liquid released from the anus.