The bolded is totally Levi. When he wants my attention, he hits me...hard! When he's upset, he is physical...even to himself. I was giving him a bath yesterday and noticed a bite mark on his knee. I asked him where he got the bite, and he said that he did it to himself.

I posted a thread not too long ago about him chewing on his fist. It's such bizarre behavior...I've never seen a child do this before.
Over the weekend, Levi was sick so he and I spent the entire day together on Friday. I realize now that the lack of attention he has been getting since little sister came home is indeed affecting him negatively. I know what it's like to be the middle child (I am one, although I've never acted out like he is doing...different personalities, I suppose), so I'm extra sensitive to that. He's been wanting Mommy a lot lately, whereas he's typically a daddy's boy...the writing's on the wall, I'm just so disappointed that I didn't see it.

Actually spending time with him alone really made me see things a bit more clearly, though, and it also reminded me of the sweet little boy he can be.
Great suggestions above. I like the positive reinforcement idea, and totally agree with following through on consequences consistently. I'll for sure be buying that book, too, Mommabert! His Aunt bought him a monster truck over the weekend that he's totally in love with. I had to take it away after he snapped my glasses in two, and it was very affective. He was upset that his favorite toy was gone, and I explained that
Mommy was sad that her glasses were now gone, too. He of course wanted to glue my glasses back together to get his monster truck back, but
I told him that his truck was going to be put away the rest of the day and that tomorrow we'd work on not being destructive to other people's things or his own. He didn't break anything the rest of the day!
Thanks again for all of the ideas! Some days, I feel so lost!!