L.R.
Please reread the posts from Karen and Kimberly--I totally agree with them both. He's normal and well aware he is competing for your attention not only with a cute baby and a demanding toddler (because all infants are cute and all toddlers active) but he also has to compete with all the attention you and your husband are giving your house right now too. Listen to those who suggest distracting him and then redirecting him into something positive -- and you'll have to think of these activities for him, not depend on him to come up with something to occupy himself while you do things around the house or tend the siblings. Ask yourself if you're expecting too much of him and expecting him to be still, to keep hands off, etc. when it's not really something he at four (barely out of toddlerhood, really) is able to do without at least some adult direction towards another activity. Kids this age have energy and must use it, but it's up to us to teach them, over time, to find outlets that are safe and appropriate, because they can't think of them for themselves yet. Find little responsibilities for him -- if he's holding the directions for you while you're installing something, or helping you paint something in the house that's appropriate for him to help with, then he can't be off ramming the wall with the stroller, etc. You and your husband might not love involving him in house chores right now becase things will take longer than if you just do them yourself, but he will feel involved, be distracted from "bad" behavior and learn to help too. Praise him a lot even for tiny things that seem to you "stuff he should be doing anyway" -- it's all a big deal to him, even if it's not to you. And unless you want to end up with his possibly hurting the baby or really damaging something, it might be time to reassess how much direction and attention he's getting amid the work on the house and the work with the younger kids. Finally -- would he benefit from going to preschool or some kind of outside activity, if he isn't already?