Despite their rather striking burnt-orange shells and their increasing popularity as pets, Madagascar giant hissing cockroaches are a vulgar, brutish kind. Named for the low growling sound they emit when disturbed, males have been known to push female cockroaches (who resist by kicking with their hind legs) into corners and take them by force. These bug-eyed bad boys like to play the odds, pursuing everything that moves — including other males — to up their chances, the theory goes, of successfully copulating with a lady. A different theory is that the he-cockroach sometimes poses as a frisky female to avoid aggression from bigger, brawnier guys, diverting their competitors. Either way, these crawlers have got lousy standards.