Hi Happymum,
Another reason for high bs most certainly could be puberty, I have a Non diabetic 13yr old, whos voice is gettting deeper (much to the amusement of his younger brother). Hair growing in all the sorts of places, (but won't let on), is moody and grazes all day long.
You may find another reason, as we found with Andrew, is that his basal runs out, when his grazing habit becomes frantic like a wild animal! We combat that by giving a 4th dose of Humalog (rather than splitting his Levemir) and so far its working. Of course its all trial and error, but if he continues to graze, he will need to bolus for it.
Suzi x