Do Animals Get Drunk?

Do Animals Get Drunk?

Some species are attracted to overripe fruits and alcohol-rich nectar.

 Here in the U.S., Thanksgiving is upon us. Some people will be very thankful there is wine at the table.

In that spirit, Saturday’s Weird Animal Question of the Week takes on Paul Anthony Kane’s question: “Do other animals consume fermented fruit, grain, and otherwise intoxicating substances?”

They do. A lot.

Butterflies, for instance, enjoy a good brew, says Katy Prudic, an entomologist at the University of Arizona: “I’ve gotten butterflies out of beer cans before."

Males likely drink beer to boost their spermatophores, nutrient-rich packages that they give to females as a nuptial gift, Prudic says.

It's not just butterflies: Many entomologists often bait insect traps with beer. If they run out, no worries—a nice pinot will do just as well.

A 2008 study found that 35 species of moths were just as attracted to traps baited with wine as with beer.

Turning to the Bottle

Other insects turn to drink when they’re sexually rejected.

In a 2012 study in the journal Science, researchers compared the diet preferences of male fruit flies that had successfully mated with those of males that had not mated.

The results showed that unmated males preferred food containing alcohol, while the mated males did not. (See: "Flies Use Alcohol to Protect Their Young from Body Snatchers.")

Further study showed that mated males had higher levels of a brain chemical called neuropeptide F, which may spike when the fly receives a reward—like sex.

Unmated mates had lower levels of neuropeptide F, which is likely why they turned to alcohol to boost their feeling of satisfaction.

Supporting this theory, unmated male fruit flies given artificial doses of neuropeptide F avoided alcohol.

Moose and Squirrel

Some mammals also accidentally get drunk—usually from nectar or fermented fruit. (See "Elephants Drunk in the Wild? Scientists Put Myths to Rest.")

Don Moore, associate director of the Smithsonian National Zoo in Washington, D.C., says via email that he’s observed the effect of overripe fruits on animals firsthand. (Also see "Why Backyard Birds Are Getting Drunk on Fermented Berries.")

“I’ve watched white-tailed deer eating fermented apples in orchards," Moore says. They get pretty “sleepy,” even “stumble-y.” It’s a common observation in apple-growing regions, he adds.

In 2011, various news outlets reported on an intoxicated moose that got stuck in an apple tree in Sweden. (Related video: "Drunken Moose.")

This video allegedly shows a squirrel that hit the fermented crabapple sauce, though Moore thinks it's more likely the animal was injured.

Flying Under the Influence

Other animals have a higher tolerance for fermented treats.

Malaysia's pen-tailed tree shrew eats nectar from the flowers of the betram palm, which has one of the highest alcohol levels recorded in a natural food—3.8 percent, according to a 2008 study in the Proceedings of the National Academy of Sciences.

These shrews can really hold their nectar: Despite boozing nightly on the high-alcohol nectar, they show no effects of intoxication.

Many bats that eat fermented fruits and nectar are also fine to fly.