The fact that grazing animals such as horses and cattle, which are vulnerable to surprise attack by predators, sleep only a few hours a day is evidence for the idea that sleep:

Question

Quizplus · Accepted Answer

Grazing animals such as horses and cattle, which are vulnerable to surprise attack by predators, sleep only a few hours a day. This is evidence for the idea that sleep has survival value. Sleep conserves energy, helps in the restoration of the immune system, and protects the animal against starvation and predation.

The Fact That Grazing Animals Such as Horses and Cattle