I went in my coop today with my kids (5, 2 1/2) and somehow the hook on the other side of the door slid just right and found it's home to LOCK the door and so there we were locked in my own chicken coop!! My kids had to crawl through the chicken door to walk around and let me out! Crazy hu? ha ha. So wish i could have seen how it locked itself! Next time I will make sure the hook is in the down position!