According to Wikipedia, Newton's Cradle is defined as "a device that demonstrates conservation of momentum and energy
via a series of swinging spheres."  I remember having one of these as a
kid.  I wish I had one now... great desk-top gadget to mess with when
bored or stuck in writer's block.  These cats in this video uploaded by Funnycatsandnicefish on October 15, 2012 are quick to catch on to
the theory of how to get Newton's Cradle going...

Do you have any science-savvy animal videos?  If so, let us know!

More cool animal videos can be found here!