While chimps are collecting rocks to throw at their human tormentors, dolphins have been observed making their own toys and playing with them for hours. The toys? Bubble rings that they make by forcing air through their blow holes. They then do all kinds of neat tricks with the bubble rings. The dolphins entertain themselves with their self-manufactured toys.
One amazing trick I saw had a dolphin blow one ring. Then another, smaller ring through the first one. Then the dolphin followed this up by scooting through the first, larger ring, after the smaller one.
The more we learn about animals, the more we become aware how much in common lifeforms have.