Bed bug adults are about ¼-3/8 inches long, oval in shape, and reddish-brown in color. They tend to be darker after they feed, so look for small blood spots or smears on mattresses or bed sheets as well. Young bed bugs are a light tan in color and can become even darker after they feed. Look for bedbugs during their feeding hours, between 2:00 AM, and 5:00 AM.