"Passalidae is a family of beetles known variously as \"bessbugs\", \"bess beetles\", \"betsy beetles\" or \"horned passalus beetles\". Nearly all of the 500-odd species are tropical; species found in North America are notable for their size, ranging from 20\u201343 mm, for having a single \"horn\" on the head, and for a form of social behavior unusual among beetles.Bodies elongate-cylindrical and black overall; ventral surfaces may be covered with yellow setae."@en . . . . . . . .