No “vegetarian” animal will refuse some protein if it gets the opportunity, cows and horses love bird’s nests from time to time. Hippos actually eat a lot of meat, sometimes more than they can digest.
As I learned from my biologist colleague, there is no such thing as an obligate herbivore. That cute little bunny would literally eat your face off if it came across your corpse.
As has been noted throughout recorded history, nature is fucking metal.