Túngara frogs are so small—about 1.5 inches—that some key robotic parts had to be placed outside the body, including the speaker needed to produce its low tones and the pneumatic pump that inflates its vocal sac with air. The frog’s builders, University of Wisconsin–La Crosse biologist Barrett Klein and Joey Stein of the design studio Moey, improved upon other fakes by replacing a fragile condom-based sac with a thicker balloon catheter. And the sac is pumped via remote control rather than by hand, so the researchers’ proximity doesn’t kill the mood. This summer, Taylor took some of the robots to Panama to test mating calls in the wild. The real female frogs were quite impressed.