A paper published recently in the journal Science finds similarities between the babbling of human infants and the babbling of the greater sac-winged bat (Saccopteryx bilineata) — a small species of bat that lives in Central and South America. As science correspondent Geoff Brumfiel reports, the researchers believe both bats and humans evolved babbling as a precursor to more complex vocal behavior like singing, or, in the case of people, talking.Wondering what similarities humans have to other animals? Email the human animals at shortwave@npr.org. We might dig up some answers.