GabyA new study found eastern hornets have an extraordinary tolerance for alcohol—unmatched by almost any other animal. Researchers at Tel Aviv University fed a group of eastern hornets alcohol solutions, including concentrations as high as 80%, for a week. Remarkably, the hornets remained alert and active. What explains the resilience of these tiny insects?
The eastern hornet (Vespa orientalis) is a medium-sized wasp with a rusty-red body and gray-yellow markings. They live in semi-arid subtropical regions of Asia, the Caucasus, southern Europe, and North Africa. By preying on honeybees, they pose a threat to beekeepers. What did the researchers discover?
Alcohol consumption is common in the animal world. We often hear about bears or squirrels overindulging. Typically, animals get alcohol from fermented fruit or nectar that produces ethanol. Most animal species—even those adapted to ethanol—become intoxicated at just 4% alcohol. Drinking alcohol can harm an animal’s health and sometimes threaten its life. However, eastern hornets tolerated ethanol concentrations up to 80% with no changes in behavior or negative health effects, even when that was their only food source for an entire week.
How was the experiment conducted, and what did it reveal? The team tested a group of male hornets to see how they metabolize ethanol. The insects were kept in boxes for a week and given only sugar solutions with alcohol concentrations ranging from 0% to 80%. During the experiment, the researchers observed the hornets’ behavior—especially their ability to build structures from soil and paper—and tracked their lifespan after the exposure. Regardless of ethanol concentration, the scientists found no effect on behavior or mortality.
“Initially, we conducted the experiment only with 20% ethanol and were already impressed,” said Eran Levin, a co-author of the study. The team had a hard time believing the hornets could handle 80% alcohol, according to IFLScience.
The secret appears to be genetic. The study’s authors attribute the hornets’ tolerance to a high rate of ethanol metabolism, likely facilitated by multiple copies of the alcohol dehydrogenase (NADP+) gene. While eastern hornets are exceptional at tolerating strong alcohol, other animals show notable resistance too: bats and primates are among the most alcohol-resistant mammals, and when given a choice, hamsters often prefer the stronger option.
The study’s results were published in the journal PNAS.
