So what do you do when your cat aids chicken escapes? Every time I come home, she's let them out again, and she just sits with them and walks with them while they are on the floor. Sometimes I come home just to chicken poo on the carpet.. she has put them back in their brooder and then she sits there and looks at me like..."What?"
I would put something heavy on top of the screen so that the cat can't flip up the lid and abet in the escape of your chickens. I put a book, piece of 2x4, etc on top of ours...it does the trick.