Spider beetles are not predators like their namesakes but are instead pests of stored grain. I was surprised at how difficult they were to photograph. Their round bodies were hard to fit into a single focal plane, while their reflective elytra were prone to harsh glare. I could not do much about the first problem, but the lighting was solved by placing the beetle inside a white box and firing an off-camera strobe into the box but away from the beetle.
photo details (both images): Canon MP-E 65mm 1-5x macro lens on a Canon EOS 20D
ISO 100, 1/250 sec, f/13, indirect strobe fired into white box