My run door was held shut with just a hook. For 5 mornings I found the hook undone. I thought perhaps I have been careless on the first morning. Finding it open five mornings in a row told me that there was a serious issue. (Don't worry my coop is VERY secure. NOTHING can get in the pop door from the run.) I installed a new latch and hook. Now the door can only be opened by unhooking a clip that takes dexterity and thumb strength, lifting the door and aligning a twist latch while pulling outward as well as undoing the original hook. I hung a cute metal rooster welcome sign on the door cause it makes noise if the door is moved. I heard the rooster sign rattling and ran out to check last night. One large raccoon went in a hurry over the chain link fence. Now I am extra glad I took all the BYC information to heart and built my run very secure as well as changing my swing pop door to one on a track that opens upward. I do think I would have been very upset if I had found my just now starting to lay hens dead in their own home.