Why Is There a Ball Inside a Spray Paint Can? #Video

Ever shaken a spray paint can and heard that strange rattling sound inside? Most people ignore it, but that tiny detail is actually doing an important job every time you use it. Inside that can is a small ball that helps keep the paint working properly—but why is it even there in the first place?

In this episode of History of Simple Things, we break down the hidden purpose of the agitator ball inside spray paint cans, how it works, and why spray paint wouldn’t function properly without it.