Three Blind Mice...

You never know when they'll come in handy so I never throw them out, even though they don't work. Thought I could cannibalise one from three dead'uns but no-chance. As soon as you unclip the roller ball device the rolling mechanism self destructs! There are at least 7 little rollers lost in the carpet, each about the size of a very small bead. The best laid plans of men with mice...