DD will be 1 yo in a couple of weeks and in the last week, she has suddenly started needing loads of sleep. Today she has had about 4 or 5 hours of napping which is about twice what she would normally have. She generally sleeps for about 10 hours at night and usually wakes up at least once in that time. Is this sudden need for sleep likely to be because of a growth spurt or something else? She's still OK in herself so I don't think it's a bug or anything.