What a man can do, animals can do even better

If you are not an animal lover you may not know that animals also take deep sleep like we do. Sleep occurs naturally in all animals as it does in humans. It is characterized by reduced interaction with surroundings, inhibition of nearly all voluntary muscles, relative inhibition of sensory activity plus altered consciousness. 

When animals are in deep sleep they do not interact with their surroundings but they can still respond to loud noises and other salient sensory events (1). 

Reference: (1) Jerome M. Siegel (2008), "Do all animals sleep?", Trends in Neurosciences 31.4.

See pictures below for more info 

Source: CCTV Facebook. 

Source: CCTV Facebook. 

Source: CCTV Facebook. 

Japanese Macaques sleeping. Source: Wikipedia 

A draft horse sleeping while standing. Source: Wikipedia