Crocodiles were played the sound of human babies crying. The higher the infant's distress level, the more the carnivores would respond.

• Nile crocodiles react to the cries of infants from species like bonobos, chimpanzees, and humans.
• The crocodiles also seem to detect distress in cries, new research shows.
• The responses may be predatory but could also show a maternal instinct.

Crocodiles are drawn to the sounds of crying babies, new research suggests.

Nile crocodiles were found to react to the cries of baby bonobos, chimpanzees, and humans — and they appear to be able to detect the degree of distress, research published in Proceedings of the Royal Society B, the Royal Society's main biological research journal, found.

Researchers played audio recordings of infants crying to the carnivorous crocodiles and discovered they were drawn to those in the most distress.