Predators save those teeth and claws for prey, or when it's absolutely necessary to do otherwise.
Well since we are talking about lions here I should probably point out that lions and hyenas DO fight a lot and try their best to kill eachother.
They most likely avoid each other. There's nothing to be gained evolutionarily by fighting.
There IS somthing to be gained evolutionarly by fighting becase lions and hyenas hunt the same prey and are locked in competion. (I should also note that hyenas are generaly more succsessful hunters than lions).
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