We recently bought 3 llamas that we're working on. We took them on a 2 mile hike the other day and passed the neighbor's mule pasture. The mules, and 1 horse, charged the fence and generally went nuts, especially the horse. They didn't run away, though. They wanted over the fence to see what these strange things were. The horse did a fair bit of bucking and farting before he decided that they weren't going to eat him.