DS (4) has sucked his thumb when tired since he was about six months old. He has had bouts of doing it more often than at other times, but recently - say, in the past month or so - is doing it sooo much; almost constantly at home.
He does some elaborate sleeve twiddling and twisting while he does it, with the non-sucking hand, so can't do pretty much anything else at the same time. He came home from pre-school upset yesterday, as the staff had apparently asked him to stop sucking when it was tidying up time (so he would actually have his hands free to tidy up! A fair request). He said they'd hurt his feelings. He also said another girl there had said he looked like a baby, which didn't seem to bother him, although I wonder if he'll feel differently about more of this kind of ribbing in the autumn, once at school.
DS's father and I separated seven months ago, so he has had an unsettling time of late. I understand his need for a bit of extra comfort, and believe children should be free to comfort themselves when tired/poorly/bored (this is why DS says he does it - he insists he isn't unhappy). However, I have read that children who suck their thumbs past about three years old are inwardly unhappy which I feel sad and worried about.
So, is this a genuine problem? Do I need to do anything about it? Or is it, as with many things, just a bit of a phase and it'll pass?
TIA