When walking on a trail, in gravel, or along a wash in Red Rock Canyon, keep your eyes out for darkling beetles (family Tenebrionidae, genus Eleodes). You’ll often find these one- to two-inch insects walking around looking for decaying material to eat. If you get too close, darkling beetles will stick their heads in the ground and aim their rears towards you as a defense againgst would-be predators. They release a foul-smelling, oily spray from their hinds that scares away many predators (similar to a skunk) when threatened, giving them the more commonly know nickname of "stink bug".
This larger desert species can spray 10-12 inches, multiple times. This defense system allows the beetle to travel freely without blending into surroundings, as its black color contrasts with light colored sand and gravel which sends a warning that it can release a foul substance. Rodents, burrowing owls and loggerhead shrikes will feed on the adult beetle. Successful predators get around the beetle’s defense mechanism by jamming its butt into the soil and eating the head and upper body.
The darkling beetle does not fly but will escape from extreme desert heat by burying itself in the sand. these beetles can scurry quickly, and walk with the front of their bodies lowered and the rear of their bodies raised. They hide under bits of debris and in the dirt during the day, and come out at night (and cooler parts of the day) to feed.