For some unknown reasons I have quite a theory for that new indie horror Five Nights At Freddy’s everyone’s been talking about.
The thing is that you can find some sort of newspaper articles, where there is a statement, saying that children were murdered by someone wearing a mascot suit. Also, some odour was coming from the animatronics, and bloodstains could be noticed near the eyes.
Apparently, the children could still be in those animatronics suit, having been powered up by the machines hidden inside. For instance, the children-cyborgs’ consciousness is off (drugged) during the day , but at night they come to life, lurking through the rooms of the pizzeria in an attempt to find the person who did this to them, and bring the judgment upon him upon stuffing in the suit. That would explain the sudden change of behaviour, as the automatic systems almost instantly put them to sleep.
Unfortunately, with the lack of eyes (you can see that in the game over screen the security guard’s eyes just fell out of their sockets), the “animatronics” can’t tell which one is the right person, so they just kill everybody.