The back biter is orneriness incarnate. Given half an opportunity, this horse will gladly latch onto an arm or leg and stare impassively at you as you try to wrest your limb from its teeth. My first piece of advice regarding this animal is that horses never smile. If you see a horse craning its neck around and offering you a wide toothy grin, rest assured that he is not showing you how profoundly happy he is to have you on his back. Somewhat relatedly, horses seldom nuzzle you with a gaping mouth.