Powderpost Beetles lay their eggs in cracks of wood and the larvae tunnel into the surface, filling it with a very fine powder-like dust. Powderpost Beetles have long, narrow, flat bodies that allow them to easily attack wood surfaces. These beetles are reddish-brown in color.
Merchant Grain Beetles are typically not found in grain products, but instead like to attack cereals, cake mixes, macaroni, cookies and chocolate. Merchant grain beetles are dark brown and have six saw-like teeth on each side of their bodies. They can grow to be one-eighth of an inch long and have very flat bodies.