Squirrels are Nuts!
The scene in "Charlie and the Chocolate Factory" with the nut-sorting squirrels isn’t so much a clever CG-animated scene, but more of a product of the genius of animal trainer Michael Alexander and his team, who actually taught forty squirrels in the span of 19 weeks to do all those tricks: from classifying which nuts go where, and chucking Veruca Salt in the bin. The only CG that was made was to make the number of squirrels appear more than there actually are. 
No wonder Veruca wanted one.