In The WildA group of horses will choose to live together. They do this for security, as a group of horses can look out for each other. They also enjoy the company of other horses.
In Domesticated SituationYou will see similar patterns of herd behavior emerging. Most domesticated horses are not kept for breeding, so there will not be a stallion present.
When a horse is lonely, it will either be dull and depressed, or excitable and anxious. The former normally occurs when the horse has been alone for a long period of time.
So, as we have learned, horses do need a companion – this is because they are herd animals, and the opportunity to socialize is one of their basic needs.