One of my horses acts like an angel with children. Give her an adult, she will make you work!
My other horse got kicked out of a therapeutic riding center because she would bite the handlers. BUT- in her defense I think it was for good reason. If she feels a rider become unbalanced, she will just stop. Won't move a muscle until you get your balance. Then she will walk on. Well, when you have kids with certain disabilities, they don't always stay balanced. She would stop, the handler would tug and tug on her halter to get her moving forward, and finally she would have enough of it and give out a little nip to the handler. One day she got a little too nippy and ended up breaking her handlers pinky finger.
Best free horse I ever got!