Inhabiting five of the continents of the world, Otters are truly amazing mammals. Otters are unique in many ways. For instance, Otters are the only marine mammals to have fur instead of blubber. There are thirteen species of otters alive today. There used to be fourteen, but the fourteenth otter, Maxwell's otter, is presumed extinct due to draining of their waters to perform genocide in Iraq. Otters are very smart; they are one of only a handful of tool using mammals. Sea Otters use rocks to pry abalone off rocks and to break open shells