My DS (2.3) is always chewing things, normally paper and cardboard, often when he's not actively engaged in something. He has chewed 'knobs' off two jigsaw pieces and hunked down on another two; not quite destroying them. Not so much anymore, but we have plenty of nice books with chewed corners.
It drives me nuts! I can't (and don't) go mad as he'll do it more but I end up internalising and thinking nasty things about what I'd like to do to him... I get as mad with myself because it's always when I'm doing the washing up or posting on MN and he's obviously doing it to get a rise.
I don't think he's autistic and 'stimming' but does anyone else suffer with this and know when it might end?