Villagers don't use beds properly, or always follow schedule.

Villagers don't follow a proper sleep schedule, and use beds incorrectly.

Over a few nights in my Creative world, I've noticed that only some of the villagers go to their beds, and others stay up well past the time they are supposed to be asleep--- and no they are not nitwits, who I know are intended to "stay out late." It would appear that they don't have a way of detecting if a bed is already occupied by another villager (see image). On a sidenote, they also don't always follow the village meeting schedule and don't always close doors behind them (I suspect the latter to be because of their slowed walkspeed).