I have a flock fifteen (now fourteen) and yesterday our light brahma hen, Haliwir kept laying down and panting. It wasn't that hot out but she did it anyways, our two roosters tried to chase her down to mate with her but they didn't look like they were hurting her. Then this morning my little sister found her dead on her back inside of the coop, so I took a look at her (with gloves!) and she felt really bloated and her vent was all purple. What happened?!