But it's not due to some anticapitalist 'eat the rich' agenda, nor is it to do with territory and aggression. The truth is, well, it's child's play.

Following years of research, a team of biologists, government officials and marine industry representatives have released their findings on just why one particular Orcinus orca group has developed this destructive streak. And it turns out, orcas – especially the kids and teens – just want to have fun. The report reveals that a combination of free time, curiosity and natural playfulness has led to young orcas adopting this 'trend' of boat-bumping, which is not at all surprising for a species that has been known to adopt odd, isolated behaviors from time to time.

In recent years, a dramatic recovery in the population of bluefin tuna in the region has been a win for a group of about 40 critically endangered Iberian killer whales that feed exclusively on the large fish. This has meant they've cut down their time spent foraging, leaving space for other 'hobbies.'

"In addition, climate change could be playing a role, leading to these tuna being in the Gulf of Cádiz continuously rather than seasonally," the scientists noted. "This year-round abundance means that there appears to no longer be a need for the whales to pursue every fish encountered."

Analyzing data collected from individual orcas and through observation, the scientists found that the 'attacks' on vessels usually involved a couple of animals at a time, from a core group of 15 that have so far been observed messing with boats. But these 'attacks' are anything but – from the orcas' perspective, at least.

Most of the 15 were male juveniles and teens, the "most curious and exploratory" of an orca population, suggesting that what started as playful head-bumping on boat rudders has escalated as the animals have grown larger. The team notes that this rudder-bumping behavior was observed around 2017, but the interactions didn't result in any boat damage. Now that the orcas are larger, their game has become a lot more powerful.

And no orca over the age of 25 – when males are fully grown – has been seen participating in the tomfoolery. Scientists suspect younger orcas have seen older siblings playing with their rudder 'toys' and then copied. (Some females have been spotted, but they're most likely there just to babysit the kids.)