The monkeys are up to their old shines at the St. Louis Zoo. And whatever you may think of their brains, just watch the balancing stunts they put on. MLS - Chimpanzees driving little cars. MCUS - A chimpanzee riding a uni-cycle. MLS - Audience applauding the chimpanzees. CUS - Two pre-teen boys. CUHS - A boy and a chimpanzee. MCUS - Chimpanzees walking in a line.