A recent survey of species intelligence yielded the surprising information that the three most intelligent species on the planet are three-toed sloths, euglenas (single-celled organisms with flagellum, which behave as both plants and animals) and a species of bacteria usually located in the lower digestive tract. The study also produced evidence to support the theory that men and women are different species: while man was only the 47th most intelligent species on the planet, woman was ranked 38th on the list.