Diabolical Diablos

Hello guys. I just need to cool my nerves by renting here. I finally found a Dino I like to play - Stegosaurus! If you get big enough, no other Dino has pretty much a chance against you. I am playing as the most pacifist person. I friendly roar even at carnos… I was growing my stego for a whole day and for the first time, I grew a Dino into adulthood… I played this Dino for like a week straight, just roaming, minding my own business. And then, two diabloceratops started to run into me from both sides. My stego was half stamina and I had no chance… I was devastated. Why would herbivores attack another herbivore without any reason? :(