A ten-month-old pet hamster residing in the Netherlands has captured global attention by logging nearly six miles of nightly running activity through a customized connection to the athletic tracking application Strava. According to owner Thijs de Buck, an MRI physicist based in Utrecht, the automated tracking setup records the rodent’s nightly distance, pace, and movement time, generating considerable online engagement across platforms like Reddit and X, along with a recent profile by Runner’s World.
The viral phenomenon began when de Buck sought to measure how much distance his pet covered after dark. Describing the setup to Runner’s World, the Dutch physicist explained that he initially installed a cheap bicycle computer equipped with a magnet and sensor to track wheel rotations. However, the hardware presented a distinctly rodent-specific obstacle: when the animal paused for more than five minutes, the sensor entered standby mode, interrupting data collection during midnight breaks.
To overcome this limitation, de Buck engineered a more robust digital system utilizing a magnet on the wheel that passes a hall sensor to detect each rotation. An ESP32 microcontroller tracks the data overnight, and a morning script on the owner’s laptop processes the information into a Strava-compatible file format, uploading the activity through the Strava API.
Online response to the tracking project has been swift.
Welfare Concerns Surrounding Small Pets
While internet users have celebrated the athletic output, animal welfare advocates and ethicists emphasize that the widespread fascination highlights broader ethical questions regarding the confinement of small rodents. Most pet hamsters are Syrian hamsters, originating from the Aleppinian plateau in northern Syria, where wild populations traverse diverse steppe terrain to forage for seeds, fruits, insects, and vegetation while constructing deep burrows.
According to Jessica Pierce, a bioethicist and author who has written extensively on the ethics of pet keeping, small animals experience significant confinement challenges. “I think that the welfare of these animals is worse than anybody else’s,” Pierce told Vox in previous commentary regarding small pets, including rodents, reptiles, fish, and birds. Confining small species to barren cages while feeding a monotonous diet of grain pellets restricts natural exploratory behaviors, leading animal welfare researchers to monitor for stereotypic behaviors such as bar-gnawing, which often signal chronic stress.
De Buck acknowledged these ethical considerations in correspondence, noting that he adopted Mollie from a previous owner who kept the animal in an even more restricted enclosure where it exhibited fence-biting and climbing behaviors. Following the adoption, de Buck upgraded the enclosure size, introduced a larger wheel, and incorporated foraging elements into the bedding. “I hope the attention that Mollie got will not result in people impulsively buying hamsters,” de Buck stated.
Commercial Breeding Practices and Regulatory Responses
Beyond individual husbandry, industry practices surrounding the commercial production of small rodents have drawn scrutiny from nonprofit animal protection organizations. An undercover investigation conducted in 2024 by the nonprofit Last Chance for Animals documented overcrowded, unsanitary conditions at a major United States rodent breeding facility, noting that animals suffered from untreated wounds, dehydration, and disease without veterinary intervention.
These findings, combined with ongoing concerns from veterinary professionals regarding the welfare of pocket pets, have prompted municipal policy changes. Cities including Cambridge, Massachusetts, and Washington, D.C., have enacted prohibitions preventing commercial pet stores from selling rodents and certain other small animals.
Animal ethicists argue that even dedicated individual enrichment efforts cannot fully replicate a natural ecosystem within domestic constraints, leaving a substantial gap between the biological needs of small pets and their captive reality. As data collection on the Utrecht hamster continues, de Buck remains curious about whether long-term activity metrics can offer further objective insights into how daily domestic routines influence captive rodent behavior.
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