Yet, jellyfish tend to sleep through the night like humans, and even nap around midday. Meanwhile, their close relative, the ...

Jellyfish sleep around eight hours a night, take short daytime naps, and compensate for lost rest,all without having a brain.

Ever wonder why some mornings you wake up ready to go, and others you feel like a zombie? The difference often comes down to when you wake up during your sleep cycle, and that’s exactly what a sleep ...