I had the same problem as Michele. My little hornb*ll will run the jennys till they just about drop :no: I would be afraid to let him in with a bred one. I think my new little guy (Casper) is going to be the same way~~ I put him in with one just to see what he would do and I'll be darn...ran her and ran her. They sure are some little Hor*y fellows. I also would not trust a jack with foals unless I was 150% sure about it, even the gentlest can become aggressive. Corinne