"Fred, why aren't you sleeping?" demanded a bleary-eyed Arthur Weasley, walking into the bedroom of his two year old twin sons. Fred was sitting solemnly awake on his bed, observing with all the importance of a two year old his brother, younger by a minute and a half, who was sleeping soundly.
"I'm takin' care o' George, Daddy," explained Fred. "Or a robber migh get 'im."
The next morning, when he came in to wake them, Fred was fast asleep on George's bed, one arm draped around his brother's shoulder, protecting him from every evil of the world.