Of those in the class _Hexapoda_, which comprises all the other known book pests, there can be no question as regards their destructiveness. Many are known about the house by the name of the article they are most frequently found in, and unless driven by a lack of those things more to their liking, they do not invade the literary sanctum. Some are so cosmopolitan in their tastes that they seem to take whatever is most convenient, whether it be books or boots, pepper or poison. As has been said, the earliest observation of value was made by Hooke on _Lepisma_, commonly known as "fish moth" or "silver fish," from its resemblance, in shape and coating, to a fish; also as "bristle tail," from its caudal appendages. They are found in closets, cupboards, and clothes baskets. Opinions have differed as to its destructiveness to books, but the weight of evidence is against the insect. It seeks the paste and sizing used about books, and this leads it to attack bindings and labels. There is a theory that paste made from pure starch is not to their liking, but this is not substantiated by observation. Termites or "white ants," another misnomer, since they are not true ants, are also well-known ravagers whose deeds of destruction assume a serious aspect, especially in the tropics. "Humboldt," according to Shimer, "informs us that in all equinoctial America, where the white ants abound, it is infinitely rare to find papers or books that go back fifty or sixty years." Their destruction to timber has been the cause of serious accidents, at one time so weakening the supports of a dwelling that a whole dinner party was precipitated from the third floor to the basement. These pests belong to the order _Isoptera_. The American species is known as _Termes flavipes_, and several well-authenticated cases of their having done serious injury to books and bindings in this country are recorded. As the chief sustenance of these insects seems to be dead wood, it may be that the increased use of wood in paper will make modern books, which bookworms are said to scorn, more tempting than ever to them. By opening quickly some old book which has lain long unused, one may see tiny pale creatures with knowing black eyes scurrying across the pages. These insects are known as "book lice," or by the Germans as "_Staublaus_" (dust louse). Entomologists have given them the high-sounding name _Atropos divinatoria_. They belong to the family _Psocidæ_, of the order _Corrodentia_. Some writers, beginning with William Derham, in 1701, are of the opinion that this delicate little creature makes a noise like unto that of the coleopterous insect called "death-watch." These little fellows are said to have stout jaws with which they do damage to books, dried plants, etc., "nibbling away the leaves and covers of the former."