Silverfish are fish-shaped insects with silvery scales covering their bodies. They are ½ to ¾ of an inch in size. Signs of infestation include feeding marks, yellow stains and black, pepper-looking feces on food sources such as wallpaper, labels and envelops. They can be found almost anywhere inside residential and commercial structures. They prefer room temperature areas with high humidity. If you identify silverfish at your property, a professional inspection followed by the necessary treatment should be done to eliminate the infestation.