We are having this issue, at least with going to bed, with our 3 year old. Are your boys still napping? Mine will still take a nap willingly, but when he does nap, he does not want to go to bed on time. He and his big sister sleep in the same room, and this disturbs her, so it was really erking me! He'd usually be relatively quiet, but come out every so often and say he just couldn't go to sleep. So this week I started putting him down for his nap much earlier than I was before, no later than 12:30, and only letting him sleep for 1-2 hrs, so he has plenty of time to get worn out again. That's worked pretty well this week. My 6 year old went through this too, waking up a lot in the middle of the night, and we did a chart with her. When she got to a star on the chart, 10 nights I think of good behavior, not getting out of bed during the night, she got to pick out a small toy at the dollar store. That worked for her. And like others have said, talking through what they're really afraid about. Good luck, it's no fun to be tired all the time!