Like stags or elephants, which use antlers and tusks to fight for dominance, male dung beetles use their horns to ward off rivals. Unlike other species, though, the male beetles can assume one of three different forms--a system known as trimorphism--based on the size of their horns: the large-horned alpha (top left), beta (lower left) and hornless gamma (lower right), which resembles the female (top right).
Since larger horns mean more mating opportunities, gammas must resort to stealth, using their meek appearance to avoid combat and sneak into the ranks of waiting females.
Image: J. Mark Rowland/UNM and Douglas J. Emlen/UM