Still enjoying green grass thanks to recent rains, three grazing mules take a break to see if the photographer might have a treat for them. He does not.
Mules, being the offspring of a donkey and a horse, exhibit good qualities of both parents for their intended use as work animals. Smaller size and appetite, endurance, health and longevity from the donkey parent (usually the male), strength, intelligence, disposition from the horse parent. And they have big ears.
Mules can reproduce, but the odds of a successful pregnancy are in the ballpark of having a winning lottery ticket.