Noise

We have some work being done on our house, so there's a ton of noise in here today. Banging, jackhammering, yelling, and just overall chaos. The babies are somehow peacefully napping through it. So why is it that they wake up the moment I tiptoe into the room? In fact, they seem to wake up the moment I even think about them waking up?

It must some sort of weird mother-child intuition thing.