Burrowing forms such as _Pycnoscelus_ may spend much time in underground cells (Roeser, 1940). Polyphagids rapidly burrow into sand (Fausek, 1906), where they may be protected from predators. Tepper (1893) discovered that a very large Australian cockroach, _Geoscapheus robustus_, had its fore legs, especially the tibiae, adapted for digging. He observed this species in captivity and in 1894 reported that it appeared to sink into the soil without raising any considerable amount above the surface and that it did not form an unobstructed tunnel. Another large Australian cockroach, _Macropanesthia rhinocerus_, burrows about two feet below the surface of sandy soil; it also makes nests among pine roots and the nymphs rarely appear above ground (Henson _in_ Day, 1950). Tepper (1893) observed that Australian cockroaches of the genera _Epilampra_ and _Oniscosoma_ buried themselves in loose soil and dust. Baker (_in_ Rehn, 1930) observed that _Styphon bakeri_ is found in humus and rubble in the Dutch West Indies where "It is sluggish in the open, but wedges into the humus quite quickly." _Therea nuptialis_, found in India, conceals itself at the roots of fig trees, etc. The small hairs on its elytra retain sufficient dust to conceal it, or at any rate to render it inconspicuous, when not on the wing (Annandale, _in_ Chopard, 1924c). Rehn and Hebard (1914) observed that the nymphs of _Blaberus craniifer_[13] at Key West, Fla., "were usually found half buried in loose damp earth under boards, where they remained motionless, looking much like lumps of earth (with which they were usually much dusted) until disturbed." Hebard (1917) reported of _Monastria biguttata_ from Brazil that "All of the juveniles are heavily coated with foreign particles" which adhere "to a multitude of closely placed, minute and usually curved spines, which cover the dorsal surface and marginal portions of the ventral surface." It is apparent from the numbers of predators reported herein that many animals are not deterred by the odorous secretions of cockroaches; these secretions, because they may seem repugnant to man, are often claimed to be repellent to predators. However, Cott (1940) points out that "There are many instances in which protective devices and associated warning colours are known to be ineffectual against certain enemies. But this does not necessarily imply that they are not on the whole beneficial to the species attacked." Certain cockroach secretions may well be repellent to many predators, but as this is a purely negative aspect of the predator-prey relationship little thus far has been observed or published. Potential prey that successfully defends itself against attack is never found in a predator's stomach.