So that's why I thought his behavior was so odd. And it changed so suddenly. He whinnies for her to come to the gate and when she does, he pins his ears and freaks out. I couldn't even get a lead on him without him pulling me around everywhere. The only thing that came to mind was that she could be in heat? Is it possible that that could be the cause of his behavior? I hope it's not that they just don't get along anymore because I would hate to have to move him so soon.