The terrified crew watched black and white shapes rise from the deep and ram the ship. A pod of orcas - named after the Roman god Orcus: ruler of the dead.

They pulled off the rudderA flat piece of a boat located near the stern. and then vanished. It is "completely extraordinary", says biologist Hanne Strager. Killer whales have never killed anyone in the wild. But after 500 similar incidents since 2020, there is talk of an "orca uprising".

The rebel leader is called White Gladis, one of around 50 critically endangered Iberian orcas. She has taught around 15 others to follow her lead.

And last month, a whale rammed a fishing boat off Shetland in Scotland. Expert Conor Ryan says it is "possible" that this "fadA craze, or intense enthusiasm that does not last for very long. " is spreading across Europe.

But why are they doing it?

"It's a game," says orca specialist Renaud de Stephanis. A three-tonne whale playing with a yacht feels aggressive to those onboard. But "if they wanted to wreck the boat," he argues, "they would break it in 10 minutes."

Play is important for learning skills. Individual pods develop their own language, hunting techniques and even fashion. For one summer in 1987, wearing a dead salmon as a hat was all the rage in the Pacific.

But ramming boats is a riskier hobby. The orcas may hurt themselves and it is unclear what they gain from the activity. Researcher Alfredo Lopez Fernandez suggests White Gladis may have been "traumatised" by an encounter with a boat.

But do animals seek revenge? A captive killer whale called Tilikum has killed three people. But in the wild, animals mostly avoid humans.

Research shows animal attacks are increasing as habitatAn animal's habitat is the place that they live in. is reduced.¹ Meanwhile, one million species are on the edge of extinctionCompletely dying out..² Hanne Strager says we will never know why the orcas are hitting boats. But the fact it feels like revenge may say something about our sense of guilt.

Yes: We should be very afraid. For too long, we have mistreated our fellow creatures and taken the natural world for granted. The more harm we cause, the more we should expect animals to fight back.

No: Using the language of revenge and war is dangerous and harmful. It will be used to justify attacks on orcas and make conflict more likely. And other animals do not share our sense of right and wrong.

Or... This is not animal revenge but it is human guilt. People are ultimately responsible for these encounters and we should do everything we can to lessen our impact on wildlife and the natural world.