Wild Things

Hamsters Don’t Eat Burritos. They Eat Each Other.

Gosh that burrito looks delicious.

Photo courtesy of Shutterstock.

A few months ago, a video made the rounds featuring a tiny hamster eating a tiny burrito. If you haven’t seen it yet, then behold the pinnacle of human-hamster achievement:

I’ll admit, this is probably the cutest thing to happen to us since baby sloths, surprised red pandas, or goats on sheet metal. Those little hands, that scrunched-up little face—I mean, these are the reasons hamsters are such wildly popular pets.

But anyone who actually had hamsters growing up, as I did, knows what should really be on that tiny poker chip plate—and that’s another hamster.

In the case of this video, we’re looking at the species Mesocricetus auratus, more commonly called a golden hamster or a Syrian hamster. Walk into any pet shop in America and you’ll find these fluffy little rodents. This is more than a little ironic since the International Union for Conservation of Nature lists them as “vulnerable” in their native habitat along the Turkey-Syria border. That’s one step above “endangered,” FYI.

It’s also strange that Syrian hamsters should be popular, considering they’re ferociously territorial. If you’re going to keep two or more adults in the same tank, they require lots of personal space. The animals have scent glands on their flanks, which they use to mark territory, so it’s also recommended that you provide separate food, water, and bedding sources. Fail to give them enough space or resources, and they’ll eat each other for fun.

I’ve seen it.

I thought I’d provided Frank and Shirley with a hamster Taj Mahal. They had tubes leading to running wheels and skylights and loop-de-loops. Fresh water and all the seeds they could eat. All the same, one day I came home from elementary school to find Shirley huddled up in a corner. What was left of Frank—a wad of wet fur, a few toothpick-like bones—lay among the wood chips.   

For her Ph.D. work on Syrian hamsters, neurobiologist Annaliese Beery wanted to study seasonality and reproduction, which necessitated breeding hundreds and hundreds of them. “I certainly never set out to study hamster cannibalism,” she told me, “but when you breed a lot of hamsters, that’s definitely something you observe.”

For those in the hamster biz, it’s accepted that more than 75 percent of Syrian hamster dams (mommies) will cannibalize part of their litter within the first day of birth. Beery’s own research suggests this estimate is probably on the low side.

In fact, in an experiment that had her up at all hours of the night checking for births, Beery found that 100 percent of her dams ate between 2 and 11 pups. (A second experiment showed a cannibalization rate of 74 percent, though Beery says they only checked the litters in the morning, which means they likely missed middle-of-the-night cannibalization in the other 26 percent.)

Why Syrian dams should be so om-nom-nommy toward their offspring isn’t completely understood. But Beery says that we have numerous “just-so stories” that make sense.

For instance, we know dams eat their young when resources are scarce. But the dams in Beery’s study had plenty of food—so they commit infanticide during both feast and famine. Her research also showed that mothers cannibalized female pups more often then males and in numbers great enough to significantly alter the sex ratio.

Beery says you can read hamster cannibalism two ways. “You could either see it as the cannibalism benefits the ones left behind because they get more milk and they grow bigger, or you could see it as the mom has eaten the smaller pups and left the bigger pups behind,” she said. “And I don’t think we can distinguish between those interpretations.”

Still, there are plenty of other species that manage boom and bust cycles without resorting to cannibalism. And isn’t it sort of wasteful for the mother’s body to build and deliver all those babies only to eat them hours after birth?

“It turns out that from an energy perspective, at least for rodents, it’s lactation, not gestation, that’s really the hard part metabolically,” says Beery. In other words, it’s a lot easier to make babies than is to nurse them.

Unfortunately for the hamsters, the carnage extends beyond birth. Syrian hamsters are solitary in the wild. When they’re not in heat, females are extremely aggressive. And because estrous occurs about one out of every four days, that means enterprising males run the risk of disembowelment about 25 percent of the time. (Remember those scent glands? A male hamster’s ability to detect estrous may save his life.)

Despite all of this, Beery says Syrian hamsters make excellent pets. They’re a lot more docile than Siberians hamsters, another pet store favorite, and they’re very friendly if handled regularly. “I just wouldn’t breed them,” says Beery. (It’s pretty easy to determine a Syrian hamster’s sex before you buy it. Their testes are what Beery called “really obvious.”)

While I’m all for letting nature take its course, I didn’t expect the next viral hamster video, below, to include wanton acts of cannibalism. The video series is actually a clever piece of content marketing by Denizen, a creative agency in Los Angeles, and the second episode premiered this week. This time, the hamster (named Bogart) attends a birthday party for a hedgehog.

Oh yeah, and that “tiny hamster eating a tiny pizza” that surfaced just days after the burrito video? That hamster is an imposter. “It’s not canon,” wrote Denizen co-founder Joel Jensen in an email. Neither is the video of tiny hamsters eating tiny tacos or tiny hamsters eating tiny Caprese salads.

“We’ll take it as imitation being a form of flattery,” said Jensen, “but hopefully people can distinguish the real thing from them.”  

Hey, I guess this means I’ll need to write about hedgehog cannibalism—because they do it, too.