I typically don’t think much about sleep. But when you fly through seven or more time zones in a single day, as I have done on more than one occasion, you think about it. When everyone else is getting up, your body is begging to go to bed. When everyone else is settling down for a good night’s sleep, your body is wide awake and looking for something to do. It takes a few days, at least, to “reset the body clock.”
Sleep is an amazing thing. We all require it, including the animals. Even my dog sleeps. I know, I have spent the night camping in a tent with him. He snores. Sleep appears to be a requirement for all animal life, though it may vary in intensity and method.