Lionfish have very low standards and will eat anything in sight. Although they're originally from the Indian and Western Pacific Oceans, these vacuum cleaners have been flopping around the Atlantic for the last 25 years, probably because people dumped them from their home aquariums. They're so stupidly hungry and abundant that sometimes, they just eat other lionfish. This would be fine if these venomous beasts just kept to themselves, but because they have very few predators in their new home, lionfish get to ruin everything else around them, too. Seriously, they're such a nightmare that scientists are trying to fight them with robots.