Trivia: The scene where Macaulay Culkin was waiting at the door for the babysitter and imagined the three burglars was the scene that inspired the box-office hit, Home Alone. (01:16:10)
Trivia: In the scene in Maizy's class near the beginning of the film, the little girl with long blonde hair sitting at the desk next to Maizy is a young Anna Chlumsky, who went on to be the star of 'My Girl' and 'My Girl 2'.
Answer: You can't actually see a person, all you see is a human-sized lump under the covers. It's possible that it's just bunched-up blankets, some pillows, or even clothes.
So, I just noticed this in the movie. If you go at about 10 minutes and 21 seconds, you'll see the blankets move behind them real fast while he's on the phone.