Scarabs were greatly revered by the ancient Egyptians because of their behaviour of rolling a ball of dung along the ground (to bury and eventually eat or use for nesting), and this was considered symbolic of their god Khepri who was thought to roll the sun across the sky each day.
The UK species of scarab beetles, however, do not roll dung balls around, but either live directly in the dung or some, like Onthophagus coenobita, excavate tunnels in the soil directly below dung of large herbivores. The forelegs of these beetles have large tibia with side protuberances, or denticles, which help in the manipulation of dung as well as digging the tunnels in which they reproduce (see close-up image). The antennae are a characteristic fan-shape with sensory receptors related to smell, and their functional hindwings (folded and protected by the hard forewings, the elytra, when not used) enables Onthophagus to fly to the location of freshly deposited excrement.
A vertical tunnel is dug below, or next to, the fresh dung, and small pieces of the dung are dragged into the tunnel and formed into a ball-shape. A single egg is laid inside a small cavity at the top of the ‘brood ball'; further balls are prepared and stacked on top. After each egg hatches, the emerging larva is surrounded by all the food necessary to develop, and turn into an adult beetle without leaving the protection of the underground chamber.
Dung beetles play an important part in the degradation of organic matter in fields grazed by livestock: the economic value to the UK cattle industry alone has been estimated as £367m!
