Here we see Viki at 8 months of age solving a non-trivial problem: finding the right string to pull on in order to get your milk. Of course, we have to remember that strings and bottles of milk on carts are not really a part of the natural world of chimpanzees. So the first thing that might surprise you is how quickly Viki pulls on that string in the first place! But then Cathy crosses the strings so that the string that is on the same side as the bottle really connects to the wrong cart. Viki isn’t fooled by this proximity. Instead she grabs the string opposite to the milk and starts pulling. Pretty smart for an 8-month-old!