Hamsters can drink the equivalent of 21 bottles of wine - and they're happy to do so

If you've ever been drinking with your friends, you probably know who's a lightweight or a heavyweight. For one, there is a break after two glasses of wine, the other drinks until dawn. But we humans are not the only ones who tend to reach for alcohol - things often get off the ground in the animal kingdom too. One animal in particular proves to be a heavyweight, even though it weighs just between 20 and 150 grams: the hamster.

That's right: The cute pets are not as innocent as their cuddly looks might suggest. The rodents can drink up to 20 grams of ethanol per kilogram of body weight. Converted to a full-grown man, that would be 21 bottles of wine a day!

Researchers have known for a long time that hamsters are small alcoholics. But just recently, a Twitter user drew the public's attention to the rodents' secret preferences. The hamster's serving of alcohol is a relative amount that "would kill a human being," wrote Tom Lawton, an intensive care physician from Bradford, UK. For comparison: in adults, five to six grams of alcohol per kilogram of body weight are considered life-threatening.

But the sweet little balls can not only take a lot of alcohol - they even like to do it. "They love it so much that they prefer drinking 15% ethanol over water," Lawton said.

Just because something is on Twitter doesn't mean it's immediately true. In this case, the cheerful (or rather: tipsy?) statements are scientifically proven. As researcher Gwen Lupfer tells The Atlantic newspaper, hamsters regularly consume 18 grams of ethanol per kilogram of body weight:

The strangest thing about the whole thing: hamsters can drink, drink, drink without even being tipsy. Lupfer found that out a few years ago. Together with colleagues at the University of Alaska Anchorage, the scientist conducted a study to measure drunkenness in Campbell's dwarf hamsters. To do this, the team developed the so-called wobbling scale. The idea is that the more a hamster wobbles while walking, the more drunk it is and the higher its score on the scale. The researchers published their results in 2015 in the journal Behavioral Processes.

The scale ran from zero - "no visible wobble" - to four - "falls on its side and does not straighten up". However, the experiment quickly showed that such a high limit would not have been necessary. Because even with huge amounts of alcohol, the rodents never reached an average value above 0.5.

It wasn't until the team injected ethanol directly into the hamsters' abdomen that the animals began to stagger -- even at lower levels. To understand this, it helps to take a look inside - more precisely, into the liver. In hamsters, the organ breaks down ethanol so efficiently that very little gets into the blood. Hence the differences in the two wobbling experiments: In contrast to the first round, where pure ethyl alcohol was administered orally, in the second run the ethanol entered the bloodstream of the Campbell dwarf hamsters directly.

But why does the rodent, which belongs to the burrowers, need this ability at all? This question is not entirely clear. One theory is that it has to do with the caloric content of alcohol. At just under seven calories per gram, ethanol has almost as much energy as fat, which has nine calories per gram.

So if a hamster consumes an alcoholic beverage or food, the extra calories could be stored in their body as fat, providing a nice cushion of warmth on cold winter days. A beer belly with a function, so to speak. Since the herbivores store their food in their burrow as a store, it could also be that they eat fermented fruits more often. Regardless of the reason why the animals consume alcohol, one thing is certain: the harmless hamster is indisputably a great drunkard.

The first experiments on the alcoholic tendencies of hamsters were carried out as early as the middle of the 20th century. In a study from 1962, researchers found that pets would rather drink alcohol than water if given the choice.

In other rodents, the love for alcohol is rather limited. For example in rats, whose consumption behavior depends on genetic factors. A researcher at the University of Chile discovered in 1960 that animals could only be motivated to drink ethanol through conditioning or genetic manipulation. But that doesn't necessarily have to be the case.

So, if someone tells you the next time you go to the pub, "You drink like a fool!", you can simply reply: "No, I drink like a hamster!" As a nightcap, we recommend the following:

This article was first published in January 2022.