Passalidae is a family of beetles known variously as "bessbugs". Nearly all of the 500-odd species are tropical; species found in North America are notable for their size, ranging from 20–43 mm, for having a single "horn" on the head, and for a form of social behavior unusual among beetles. They are able to produce fourteen acoustical signals, more than many vertebrates. Adults produce the sounds by rubbing the upper surface of the abdomen against the hind wings. The larvae produce the sounds by rubbing the third leg against a striated area on the coxa of the second leg.
From album: National Parks and examples of Linking Tourism & Conservation of Ecuador