A female horse, known as a mare, is an adult horse that is typically over three years old. Mares are known for their nurturing behavior, especially when they give birth to foals. They can vary in size, breed, and color, and are often used in various equestrian activities, including riding, racing, and work. Mares usually have a reproductive cycle that lasts about 21 days, during which they can become pregnant. They are often bred for specific traits, such as speed or temperament, and play a crucial role in the horse industry. Proper care and management are essential for their health and well-being.