In order to go to sleep, dolphins and whales don’t have to conk out like us weak humans. They can turn one half of their brain to “sleep mode,” while the other half is still happily chugging away at the problems of swimming, eating fish, and not dying.

While that is totally crazy, it’s not exactly news. Scientists have known about dolphins’ secret for a while. What they do not know is how long dolphins can keep this up. A couple of years ago, one team figured out that dolphins can stay alert for five days and nights straight. Impressive enough. We can barely stay awake until 11:30 p.m. some nights. But now another team of scientists has kept two dolphins awake for 15 days straight

The whole time, the scientists had the dolphins use their powers of echolocation to look around them for particular targets. One of the dolphins continued to do this with 97 to 99 percent accuracy. The other one was not quite as good at not sleeping and only achieved 75 to 86 percent accuracy. Which is a B or a B minus, which, as any high school or college student can tell you, is still pretty good when you’ve pulled more all nighters in a row than you ever thought possible.

The craziest thing about this is that the dolphins could have kept going. About the more successful dolphin, the scientists wrote, “SAY displayed no indication of deteriorating performance. How much longer she could have performed the task is unknown.” Basically, she could maybe stay awake forever and stay just as smart. So assume the dolphins are watching. Always.

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