my 2 yr old daughter does the same thing. It drives me crazy, especially when its in the middle of the night! In our case it generally results in not letting (or not knowing) that she wanted to do something herself. LIke if I get her a fork out of the drawer and she wanted to do it herself, I have to put the fork back for her to get. So I'm learning to prevent the meltdowns. When they do occur I find any distraction great. ("look at that bird") or "let's call Daddy at work". Anyways, I have a boy the same age as your twins..I can't imagine having two! Lots of luck!