Nightlatches (also commonly referred to as Yale locks) are usually accompanied with a deadlock on the front door of a house for optimal security. A night latch has a spring lock that can be opened from the inside just by turning the handle without the use of a key and requires the use of a key to be opened from the outside. Night latches lock automatically once the door is closed and they hold the door closed with a latch which can be deadlocked into position.