This influencer runs 6 miles every night. He’s also a hamster.

We know this because, a few weeks ago, a Dutch physicist named Thijs — who owns Mollie — rigged up the rescued hamster’s running wheel to Strava, a popular app that runners use to log their miles. Thijs found that Mollie typically runs around six miles every night.

“He’s beating me,” Thijs told the CBC. “Almost 70 kilometres a week, which I think many people doing marathon training would be happy to hit.”

The internet loves a quirky animal story, and this one has gotten plenty of attention on Reddit and X. Mollie even got a recent profile in Runner’s World, and he now has over 9,000 followers on Strava. Mollie’s Strava updates are headlined with cute puns like “No Rest for the Whiskered,” and “The Fast and the Furriest.”

I get why so many people are cheering on Mollie and his commitment to going the distance: Hamsters are adorable, and the idea of one logging miles on Strava is extra charming. But the light-hearted virality of the story masks a fundamental problem with owning small pets like hamsters. Mollie evolved to run in an open and diverse ecosystem, but he lives in a small cage and doesn’t have much to do besides circle endlessly in a simple wheel.

Most pet hamsters are Syrian hamsters, native to that country’s Aleppinian plateau — steppe terrain in the northern part of the country. In the wild, they regularly traverse the landscape to forage for food, consuming a wide sampling of seeds, fruits, insects, and green vegetation. They store their haul in their cheeks while journeying back to their two-foot deep burrows.

But, as pets, they’re largely fed a monotonous diet of grain pellets and are confined to tiny cages where they can’t engage in their natural behaviors, like building proper burrows, traveling for food, and exploring their turf. Confining a dog or cat in a kennel for all or most of their lives would no doubt be a severe form of cruelty, yet we’ve normalized doing so for small animals whom we’re less likely to view as capable of suffering, even though there’s no scientific basis for that assumption.

And while you might think it could be nice for an animal to not have to work for their food, research has found that many species don’t like to freeload (cats might be one exception). On top of all of that, according to some research, these smaller pets are less likely to receive veterinary care to address their ailments and injuries than cats and dogs.

Their tedious and confined existence can contribute to “stereotypic” behavior: repetitive motions, like gnawing on cage bars, that are indicators of stress. Some animal welfare researchers have proposed that wheel use could also be a sign of stress — or that it could indicate an urge to run or escape. One other study suggested it might help reduce other stereotypic behaviors.

“I think that the welfare of these animals is worse than anybody else’s,” Jessica Pierce, a bioethicist and author of several books on the ethics of pet keeping, told Vox for a previous story. She was talking about small pets in general — not just hamsters, but also species like snakes, fish, and birds, most of whom are still much more wild than our domesticated cats and dogs (who also might not be as happy as we think).

Thijs, for his part, is sympathetic to these concerns, which he told me over email were fair. “I hope the attention that Mollie got will not result in people impulsively buying hamsters (and then forgetting about them after it turns out their hamsters just sleep 80% of the time),” he said.

He adopted Mollie from someone who could no longer take care of him and who kept him in an even smaller enclosure. “[Mollie] showed some behaviour that really concerned us back then (climbing, biting the fence, etc),” Thijs said over email. So, within the first week, he upgraded Mollie to a larger cage and a larger wheel and got him some toys, which seemed to improve his mood.

“I think some behavioural aspects (more running, digging tunnels in the bedding, ‘foraging’ if we hide food in the bedding) make his behaviour closer to natural, but it’s, of course, never like in the wild,” he said. Thijs also wonders whether his data-gathering might provide insight into how certain actions — like when he cleans Mollie’s bedding or when he stays up late watching Netflix — affects Mollie’s running behavior.

“People often talk about pets being ‘happy,’ but, especially with small animals, that’s difficult to assess objectively,” he told me. “I’m curious whether long-term activity data might give us useful clues about changes in his behaviour or wellbeing!”

While Thijs adopted Mollie, there’s also the question about where many of these pets come from. A 2024 undercover investigation by the nonprofit Last Chance for Animals into a massive US “hamster mill” documented thousands of rodents being bred and raised in overcrowded, small, barren cages. Some of the animals were dehydrated, diseased, and suffered from wounds. Individual animals weren’t provided with veterinary care, and breeding hamsters whose production dropped — along with litter runts — were gassed to death.

Investigations into other rodent mills have found similar problems. Such investigations, combined with veterinarians’ concerns with keeping small animals as pets, has driven some cities — including Cambridge, Massachusetts, and Washington, DC — to prohibit pet stores from selling rodents and other small pets.

I don’t mean to single out Thijs for his interesting experiment, especially considering he adopted Mollie and immediately improved his life. But animal ethicists like Pierce argue that however much effort one puts into giving these small pets a better life, it likely doesn’t ever add up to a good life, considering the constraints of cage confinement and other common care issues.

To Pierce and some of her colleagues, the sizable gap between what small pets need and what they often get reveals a largely hidden but serious crisis of animal neglect and suffering. And that’s rarely mentioned, if at all, in viral social media posts or news articles about these critters.

If we take a moment to pause and see Mollie’s life for what it is — and examine the industry that breeds these small animals for profit — all those miles he’s logging on Strava seem more like daily posts saying that he’s striving for a far different life with no way to get there.

“This entire ‘track his runs on Strava’ thing started off more as a geeky side-project, I never expected it to get anywhere near this much attention,” Thijs told me. “But it’d be nice if you can use it as a way to educate people (including me!) about the ethical considerations!”