A couple of very clever bell-ringing cats, watched as colorful stacked dominoes toppled along a rolling Rube Goldberg track in front of them. When it came time for each play a part in the works, each kitty performed excellently, eventually sending the rolling ball back to where a nice treat waited for them.
A few weeks earlier, the tabby had found that he could start a domino toppling process just by simply ringing a bell.
