Son is terrified of them. He's 4. He hides under his bed sobbing and shaking when they're going off and I have to go and get him and put him in my bed and lay with him until they've stopped. I've tried everything and thought I had some good techniques down to help him but they've just started and he's now in the bath crying with his ears under the water so he can't hear them. I'm at a loss. Does anyone have any tips?