I kept missing eggs too and couldn't figure it out. We had a cute little urban coop, about 2.5' off the ground. The ramp always fell but the hens liked to jump/fly into it to lay their eggs. It was a mini barn shape (about 2x3 with a little door) and two laying boxes off the side. One day while at the kitchen sink, I saw a flash of black and white at the coop door. I thought a skunk had jumped up into it, but about 5 seconds later, my 55 lb border collie turned himself around and jumped out with an egg in his mouth! I was shocked! I still have no idea how he could fit through the door, much less get an egg and turn himself around in the little space! When we expanded our coop, we had to put latches on the lids of the nesting boxes because he would push them open with his nose, stand on his hind legs, and help himself to egg treats! If you have a dog, that would be my first guess. Good luck!
