Want a secure flock, but don't feel like hand locking a latch or padlock on your coop door every night? Well look no farther! This vertical door slides easily with the small tug of a string that is conveniently located outside your coop. Most importantly, the coop door self locks from the inside as it is lowered, making it IMPOSSIBLE for those darn predators to even TOUCH the lock. If that wasn't enough, this design eliminates the ability to externally lift the door from its bottom.