They are a particular threat to paper and paper products, and the glue used in book and magazine production. Silverfish are able to extract nutrients from the cellulose fibers in paper products. There are thousands of cockroach species in the world, but only a handful that are pests. Control measures commonly involve sprays or dusts. Sprays are easier to apply, but dust will get into tight areas where cockroaches live.
Control is enhanced if one cleans the area before applying chemicals.
This group of insects is the least commonly seen of all the household pests. They infest wood, and must rely on protozoa and bacteria in their guts to break down the cellulose of the wood. Fortunately, bed bugs are no longer common as pests in households in the United States. In earlier decades, these blood-suckers were an annoying problem, and would also be found in the seats of trains, trolley cars and theaters. The origin of bed bugs appears to be from parasitism on bats in caves.