dung beetles

...these would be the beetles of choice. Onthophagus taurus dung beetles, showing size and horn variation among males. Dung beetles in the widespread genus Onthophagus sport a bewildering array of horns. Not only do the horns of different species vary in shape, size, and the body part from which they grow, many species show a marked dimorphism within the males. Consider these two male morphs of O. nigriventris, an African species: The big guy on the right is a major male, and he does pretty much what you'd expect. He bullies his way around with shows of bravado, guarding his burrows with…