A man’s penis has one head. The spiny anteater’s penis has four heads. When scientists tried milking semen from the spiny anteater, they were puzzled by the massive four-headed monster that emerged. The scientists were unable to get a drop from the well-hung fellows either - although I don’t know what part of electric-stimulation they were supposed to enjoy. What was more puzzling was the fact that females only have two points of entry. Apparently, during a normal erection two heads get shut down and the other two slip right in to the female. More bizarre is the fact that the heads used are swapped each time the spiny anteater has sex. Video and source in the full article

Via NewScientist