First, orcas started attacking boats.
And now, scientists have caught octopuses punching their fish companions on camera.
A video shared by Nature Publishing Group shows clip after clip of octopuses feeding their marine mates a knuckle (well, sucker) sandwich.
Filmed by scientists at the Max Planck Institute of Animal Behaviour, the compilation seems to prove our favourite cephalopods have a mean streak.
But speaking to BBC Science Focus, Dr Eduardo Sampaio, the lead author of the study behind the footage, said there are methods behind the boisterous behaviour.
Which are?
Scientists discovered that octopuses, typically considered solitary creatures, can sometimes team up with fish to hunt food.
“Fish serve as guides, finding prey and flagging its location, and the octopus uses its flexible arms to capture the hidden prey,” Max Planck Institute of Animal Behaviour’s site reads.
Different fish have different roles, and there’s a distinct hierarchy in the food-finding pack, Dr Sampaio said.
The octopus is the “de facto leader” of the group, the paper his team wrote on the subject revealed.
So, when a fish breaks rank by getting in between the boss and his dinner, he’s banished to the outer edge of the feeding frenzy with a swift punch.
This may both exclude the offending fish and deprive him of food, researchers say.
“It turns out that the punching is directed to fish that try to exploit the octopus and the group, particularly the blacktip grouper species,” Dr Sampaio told the BBC.
Octopuses use the technique to hurry their crew along too
“We found that punching is also associated with the group’s movement,” Dr Sampaio added.
“That is, if the group is too clustered around the octopus and doesn’t move through the habitat, the octopus punches fish in order to show this negative feedback.”
They don’t punch fish that are moving “as there are prey opportunities being created for all members of the group.”
By the way, punishment only goes one way in that dynamic – octopuses can punch fish, and fish headbutt one another, but fish in these packs have never been seen trying to retaliate against an octopus.