New robot frog gets into fights

Finally: A robot that provokes male frogs enough to start a brawl.

That engineering triumph brings hope to Peter M. Narins of the University of California, Los Angeles. He and his colleagues have been trying to decode the communications of the brilliant-thighed dart-poison frog, Epipedobates femoralis, but they couldn’t get the frogs to finish an interaction.

Males of this tiny tropical species stake out territories on the forest floor.