Chimpanzees engage in cheeky trendsetting behavior — proving they're more human-like than you realize, study reveals

New York Post

10-07-2025

Move over, fashion week — the hottest accessory of the season is a blade of grass shoved in your ear. Or, for the truly daring: your butt.
Chimpanzees at a Zambian wildlife sanctuary are going viral — not for escaping or throwing poo, but for their bizarre behavior that's as puzzling as it is cheeky.
At the Chimfunshi Wildlife Orphanage, one group of captive chimps has taken to dangling grass out of their ears, a trend researchers first spotted back in 2010, originally reported on by Live Science.
But now, a second chimp clique has upped the ante — by sticking it where the sun don't shine.
Yes, you read that right. A new study published July 4 in the journal 'Behaviour' reveals the latest primate pastime involves wedging grass into their rectums and letting it hang like the world's worst tail.
Why? Even the experts are scratching their heads.
The first trendsetter, a female chimp named Julie, kicked off the grassy-ear craze over a decade ago.
After she died in 2013, her son and a few others kept the tradition alive. But it wasn't until 2023 that the butt-branch brigade burst onto the scene.
Enter Juma — a male chimp and apparent innovator — who debuted the rear-end version of the fad, which spread faster than lice in a middle school locker room.
A new study published July 4 uncovers the chimps' latest pastime: stuffing grass up their behinds and letting it dangle like a sad excuse for a tail.
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Within a week, his entire group was in on the gag — er, grass.
Researchers, who watched the apes closely over a year, say the trend isn't about hygiene or comfort. It's all about clout.
'In captivity, they have more free time than in the wild,' van Leeuwen said. 'They don't have to stay as alert or spend as much time searching for food.'
So with extra downtime and no TikTok to scroll, these chimps are showing off their flair — and perhaps strengthening their friend groups in the process.
'It could also serve a social purpose,' van Leeuwen added. 'By copying someone else's behaviour, you show that you notice and maybe even like that individual. So, it might help strengthen social bonds and create a sense of belonging within the group, just like it does in humans.'
As The Post previously reported, wild chimps in West Africa were recently caught on camera cracking open cold ones of their own — in the form of fermented African breadfruit laced with booze.
Researchers from the University of Exeter spotted the buzzed behavior in Guinea-Bissau's Cantanhez National Park, where the furry foragers shared the fruit — which clocked in at a light 0.61% ABV — in what may be the original happy hour.
'For humans, we know that drinking alcohol leads to a release of dopamine and endorphins, and resulting feelings of happiness and relaxation,' ecologist Anna Bowland, lead author of the study, noted in her report.
Experts say life in captivity gives chimps plenty of downtime — with meals delivered and no predators to dodge, they've got extra time to get weird.
Kitch Bain – stock.adobe.com
While the chimps likely didn't get tipsy off the low-proof fruit, scientists are digging into whether these jungle juice hangouts are rooted in early evolutionary bonding rituals.
Overall, Charles Darwin never said evolution would be glamorous — just weirdly on-trend.