COCKROACHES AND HOUSE ANTS. 87 



the moviug of furniture or disturbed in their hiding places, they are 

 rarely seen, and if so uncovered, make ofi' with wonderful celerity, with 

 a scurrying, nervous gait, and usually are able to elude all efforts at 

 their capture or destruction. It may often happen that their presence, 

 at least in the abundance in which they occur, is hardly realized by 

 the housekeeper, unless they are surprised in their midnight feasts. 

 Coming into a kitchen or pantry suddenly, a sound of the rustling of 

 numerous objects will come to the ear, and if a light be introduced, 

 often the floor or shelves will be seen covered with scurrying roaches 

 hastening to places of concealment. In districts where the large 

 American roach occurs they sometimes swarm in this way at night in 

 such numbers that upon entering a small room in which they are con- 

 gregated one will be repeatedly struck and scratched on the face and 

 hands b}^ the insects in their frantic flight to gain concealment. 



The black roach is less active and wary than the others, and particu- 

 larly the German roach, which is especially agile and shy. 



The domestic roaches are practically omnivorous, feeding on almost 

 any dead animal matter, cereal products, and food materials of all sorts. 

 They are also said to eat their own cast skins and egg cases, and it is 

 supposed that they will attack other species of roaches, or are, perhaps, 

 occasionally cannibalistic. They will also eat or gnaw woolens, leather 

 (as of shoes or furniture), and frequentl}^ are the cause of extensive 

 damage to the cloth and leather bindings of books in libraries and 

 publishing houses. The sizing or paste used on the cloth covers and in 

 the binding of books seems to be very attractive. Tlie surface of the 

 covers of cloth-bound books is often much scraped and disfigured, par- 

 ticularly by the German cockroach [Ectohia f/ermanica), and the gold 

 lettering is sometimes eaten off to get at the albumen paste. On ship- 

 board the damage is often very extensive, on account of the vast num- 

 bers of cockroaches which frequently occur there, and we have reliable 

 accounts of entire supplies of ship biscuits having been eaten up or 

 ruined by roaches. 



The damage they do is not only in the products actually consumed, 

 but in the soiling and rendering nauseous of everything with which 

 they come in contact. They leave, wherever they occur in any num- 

 bers, a fetid, nauseous odor, well known as the "roachy" odor, which 

 is persistent and can not be removed from shelves and dishes without 

 washing with soap and boiling water. Food supplies so tainted are 

 beyond redemption. This odor comes partly from their excrement, but 

 chiefly from a dark-colored fluid exuded from the mouth of the insect, 

 with wbi(;h it stains its runways, and also in part, doubtless, from the 

 scent glands, which occur on the l)odies of both sexes between certain 

 segments of the abdomen, and which secrete an oily liquid possessing 

 a very characteristic and disagreeable odor. It freipiently happens 

 that shelves on which dishes are placed become ini])regnated with this 

 roachy odor, and this is imparted to and retained by dishes to such an 

 extent that everything served in them, particularly litjuids, as coffee or 



