My 22 month old ds has always slept quite a lot, for a long time his usual pattern was about 12 hrs at night and 2.5 - 3 hours during the day. Almost overnight he changed to sleeping 11 hrs at night and only 1.5 hrs during the day. I know it's not major, but does their sleeping pattern normally change so abruptly? I notice that he still seems to be a bit tired through the day but won't sleep for any longer.