I was out lunging my horse and she got upset about something I asked her to do and actually turned around and lunged at me like she was going to bite me. I sidestepped and was about to smack her a good one, when she must've caught the expression on my face (I hadn't said a word or even changed the position of my hand yet) and started backing up like she was on fire. I just started walking towards her, and she kept on backing up until she couldn't go any farther. I looked at her for a couple of seconds and then grabbed her halter and started working her again. She straightened right up. Easiest punishment I've ever given.
The funny thing is, I've never hit her and she's not scared of people. I guess she's a horse with a conscious.