AP BIOLOGY

Detailed explanation-1: -They can sleep while standing, an adaptation from life as a prey animal in the wild. Lying down makes an animal more vulnerable to predators. Horses are able to sleep standing up because a “stay apparatus” in their legs allows them to relax their muscles and doze without collapsing.

Detailed explanation-2: -Horses are adapted to run, allowing them to quickly escape predators, and possess an excellent sense of balance and a strong fight-or-flight response.

Detailed explanation-3: -Horses are highly social herd animals Horses that live in herds and graze naturally get to exercise their senses frequently. For example, they smell each other when greeting and they smell each other’s dung. They use their visual and hearing senses to look out for and listen for danger.

Detailed explanation-4: -Horses have a unique structure called the guttural pouches in their throat area, which are essentially large air pockets that arise from the eustachian tubes. The major artery that supplies blood to the brain passes right through them; many believe these air pockets cool the blood before it enters the brain.