I don't know what's going on, but I've had three out of ten hens with prolapsed vent in the last few days. I've dealt with this before but with one hen. They have tons of space in coop and enclosed run, feed in the coop, and water in the coop and run. Oyster shell provided and sand bedding in coop and run. Any ideas why this is happening to so many at once? Thanks for any help.