“Horses can doze standing up thanks to a "stay apparatus," a system of tendons and ligaments that locks their legs in place, but they need to lie down for deep REM sleep.”

Reference: American Association of Equine Practitioners (AAEP)

More animal facts

The harmless whale shark holds the title of largest fish, with the record being a 59 footer captured in Thailand in 1919.

A 1,200-pound horse eats about seven times it's own weight each year.

An albatross can sleep while it flies. It apparently dozes while cruising at 25 mph.