Kids damage their teeth crunching sugary candy and chips. Dogs damage their teeth chewing bones and rocks. And recent research suggests that killer whales may damage their teeth munching sharks.

It turns out that some Orcas have a taste for these deep-sea predators. Unfortunately, overindulging in shark meat can pose problems for a whale’s mouth. Over time, thorn-like barbs in the shark’s hide grind down the whale’s teeth.

While ocean scientists have long known that fish and sea mammals make up the menu for killer whales living in shallower waters, this new research casts light on the feeding habits of so-called “offshore” Orcas, whose deep-water ways have always been something of a mystery.