I wanted to give a heads up to everyone about my recent experience with aspen shavings. A few days ago I switched from grass hay to aspen shavings, having read that they are safe. I was really happy with it, the eggs were so clean. All my hens use the same milk crate (there were 5 hens), so I've removed all but the one box. Yesterday I went to lunch and when I came back one hen was upside down under the box (maybe seizure activity toppled it?), and one was dead right next to that. The one was still barley alive and I tried to do CPR on it. There was mucous coming from her beak and very liquid sounds coming from her chest. I couldn't save either. Now, I live in Louisiana, but they had water. And the others seem ok besides upset today. I don't know for sure what killed the other 2, but I do know I will never take a chance with wood shavings of any kind again.