Mules are hybrid animals that result from breeding a male donkey, known as a jack, with a female horse, called a mare. They are known for their strength, endurance, and sure-footedness, making them valuable as working animals in agriculture and transportation. Mules typically inherit desirable traits from both parent species, such as the horse's size and the donkey's hardiness. Mules are generally sterile, meaning they cannot reproduce. They come in various sizes and colors, depending on the horse breed used in the crossbreeding. Due to their intelligence and strong work ethic, mules are often preferred for tasks in rugged terrains, such as mountain trails and farms.