Cockroaches 



The cockroaches which have just been mentioned are practi- 

 cally domesticated animals in so far as they have accommodated 

 themselves to the environments of civilization. They appear to 

 eat almost everything, v^hether animal or vegetable in its nature, 

 and they are household pests of the highest rank. They are also 

 all of them cosmopolitan, or practically so, and have been carried 

 in ships to almost all parts of the world. Our native cockroaches 

 are, most of them, out-door feeders and are exceptionally cleanly 

 insects. In f^ict, any one of the domestic cockroaches, if 

 watched, will be seen constantly to make efforts to beautify its 

 person, licking its legs and its antennae in much the same manner 

 in which a cat washes its paws. A curious observation which 

 the writer once made indicates that it is possible for cockroaches 

 to acquire the tobacco habit. A croton bug of the usual inquisi- 

 tive turn of mind inhabited my office 

 desk, and as soon as I laid down my 

 cigar upon the edge of the drawer the 

 little fellow invariably came out of his 

 hiding place and worked vigorously at 

 the moist end. At first he was after the 

 moisture but later the tobacco taste grew 

 and he became as much addicted to the 

 habit as the most inveterate human to- 

 bacco user. It maybe worth mentioning 

 that it seemed to have no appreciable 



effect on its health. Fig. aig.-Periplaneta 



onentalis. 



Cockroaches are fond of darkness. 

 They roam about houses at night, and new houses become 

 stocked with roaches through migrations at night time from 

 over-supplied adjoining establishments. On a dark day in Wash- 

 ington I once saw a migrating army of cockroaches, incalculable 

 in number, crossing the street from a dirty restaurant toward 

 buildings opposite. The majority of the individuals composing 

 the army were females carrying egg cases, and the observation 

 thus became one of psychological interest since the migratory 

 instinct seemed to have been developed by an appreciation of the 

 fact that while the restaurant might support the mothers there 

 would not be food enough for the coming children. 



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