From an evolutionary perspective, you’d think stressful experiences would require high alertness. But sometimes, stress means going to sleep, reports The Atlantic.

One relevant situation you’ve probably experienced—and that you share with a lot of the animal kingdom—is the overwhelming snooziness that comes with fighting off an infection. In some creatures, even overheating triggers a nap. And for certain people, the stress of an argument can send them to slumberland, a take on “fight or flight” that seems to make little sense in terms of survival.

Scientists have studied such stress-induced sleep, which is different from the circadian sleep we indulge in every night, in rabbits, mice, and even roundworms, in search of an explanation for why this happens. Now, a new paper in the journal Genetics reports an intriguing finding: A gene that helps repair damaged DNA is involved in putting roundworms under when they are stressed.