Little frogs can make a lot of noise, as Malaysian and German scientists in Borneo discovered when they went searching for the critters making the rasping sounds that usually begin as the sun goes down. Tracking the calls to pitcher plants, the researchers laid out a white cloth and tapped the leaves to see if anything emerged. Out jumped copper-colored frogs about 10 mm (0.39 in.) long, the smallest adult frogs ever seen. How small? Put one on the edge of a penny and it has to make at least one big hop to reach Lincoln's head.