What was tin foil collected and used for in world war 2?

Radar "confusing" chaff. As a kid during WWII, at night, we sat around the kitchen table rolling aluminum foil into big balls. We thought it would be melted down. We hadn't even heard of radar. The balls were then shreaded and the little flakes were dropped from aircraft as they entered enemy airspace and caused radar controlled weapons, such as Germany had, to miss their target and to confuse radar operators as to the number of incoming planes.