The horse is a domesticated one-toed hoofed mammal. The horse evolved over the past 45 to 55 million years from 'Eohippus', a small multi-toed creature, into the large, single-toed animal of today. Humans began domesticating horses around 4000 BC.

Horses are adapted to run, as this trait allows them to quickly escape predators. They are able to sleep both standing up and lying down, with younger horses tending to sleep significantly more than adults. Female horses, called mares, carry their young for approximately 11 months, and a young horse, called a foal, can stand and run shortly following birth.

Most domesticated horses begin training under a saddle or in a harness between the ages of two and four. They reach full adult development by age five, and they have an average lifespan between 25 and 30 years.

Horse breeds are loosely divided into three categories based on general temperament. There are spirited "hot bloods,” which are known for their speed and endurance. "Cold bloods,” such as draft horses and some ponies, are more tempered and suitable for slow, heavy work. “Warmbloods" developed from crosses between hot bloods and cold bloods, often focusing on creating breeds for specific riding purposes, particularly in Europe.

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