If you peel back the bark of an old stump in the forests of western North America, there's a good chance you'll find some of these attractive tank-like insects. This is Ostoma pippingskoeldi, a predatory beetle in the family Trogossitidae. They lurk about under bark searching for soft-bodied prey, including the larvae of other beetles.
Photo details (top): Canon mp-e 65mm 1-5x macro lens on a Canon EOS D60
ISO 100, f13, 1/200 sec, diffused flash
(bottom): Nikon coolpix 995, ambient light
Tank-like is an accurate description. With all the timber downed in a 2008 ice storm, we ought to have a good crop of these beetles and their prey.
I love how they even tuck their antennae tidily out of the way.