Names: An adult female horse is called a mare, the adult male is called a stallion. A foal is a horse not yet one year old; a colt is a young male and a filly is a young female. A gelding is a sterilized male horse. A pony is a small horse, less than 58 inches (146 cm) tall at the shoulder. Horses are closely related to the zebra and donkey. Mules and hinnies are the offspring of donkeys and horses. The genus and species of the horse is Equus caballus.

Anatomy: Horses have hoofed feet (they are ungulates). The hooves and teeth continue to grow throughout the horse's life. Horses have a narrow, flowing mane. They have large nostrils that let them get lots of air quickly. Large eyes and ears help the horse detect predators early, allowing it to run away. The heaviest horse is the Belgian (up to 3,150 lb,1400 kg), a draft (working) horse; the tallest is the Percheron (7 ft tall), another draft horse. The lightest and smallest is the miniature horse, a type of pony.

Sleeping: Horses sleep standing up, but if they feel safe, they will sleep lying down.