One of our (inside) cats has started escaping via the window used by the aircon. He quite literally pulled the board out of the window last night. Any ideas on how to prevent him from getting out there without losing use of the aircon? My housemate has an idea of using springs to pull the window closed if the board is removed, would that work? And not injure the cat in the process? Are there even stick on hooks (we can't drill into the window frame) strong enough to attach the springs to?