Your son sounds like a very normal 3 year old with a new baby brother! His world has been turned upside down. Can YOU sleep when your world is turned upside down? He will eventually settle into life as an older brother but meanwhile his nervous system is reacting to the stress of it all. You can wait it out patiently or help it along a little with Bach Flower Remedies (try a mixture of Star of Bethlehem for the shock of losing his place as only child and Agrimony for internal conflict that disrupts his sleep even though he looks perfectly happy during the day). If these remedies don't work, consult a Bach Flower Practitioner to tailor-make a mixture for him. You can learn more about the remedies at www.bachcentre.com.  As for waking the baby, try to remove your toddler from the sleeping baby's presence. Don't give him a lot of attention when he wakes the baby - in fact, show a bit of very quiet non-approval and that's it. He'll eventually outgrow this behavior as he gets more accustomed to the baby living in the family.  All the best,  Sarah Chana