Hardwood From Hardest To Softest Why Does My Son Bang His Head And How Can We Prevent Him From Doing It?

Why does my son bang his head and how can we prevent him from doing it? - hardwood from hardest to softest

When my son was tired and frustrated or angry, he bends his head on the surfaces of the expression really hit. Sometimes, the soft surface of the cushion, sofa, or it may be a window sill or on a table or floor. When it comes to a smooth surface, he repeatedly struck his head, but with hard surfaces, strikes and it is usually wrong. It is a little more intelligent than 20 months. If you touch something hot to touch ever again. Touching a thorny plant that turns from him because it hurts, but that does not seem to learn. How can we prevent them wear it without recourse to a helmet all day?