is it some kind of extension of themselves? why do they need to do it?
ds1 has a kind of imaginary friend. She is called Alan and she lives in Iceland.
the problem is, he wants to send her things in the post, only we don;t know her address! He invites her to his birthday parties and gets terribly upset that she doesn't come, he wants to go to Iceland on holiday and visit her and is very very excited about the prospect.
He is 5, and he knows that she isn't real... doesn't he???