|1 of 6. Mules were brought to Hawaii from the mainland to work on the sugar plantations. There are no longer sugar plantations on [The Island of] Hawaii and many of the mules that are left from the sugar cane era spend their days hauling tourists. A mule is a cross between a horse and a donkey. They are surefooted and less flighty than horses and often live up to 40 years. According to their handlers, mules are more intelligent than horses. (Sorry horse lovers). This part of the island is known for gray skies and it rained during most of the ride. But it was a warm.