Four AM I heard the squwak of distressed chickens, I ran out ot the pen and three of my five were dead, heads bitten off of two of them. I thought this was secure enough, but evidently it wasn't. I replaced the roof and locked the other two birds in the coop. At 6:30 I went back outside and the roof was again pushed open. The two hens were safe but really spooked. So I rebuilt it like this, and wired shut all the roof sections. Now, I'll have to buy some more hens next week.