130 HOUSEHOLD INSECTS 



doubted migration of cockroaches from one building to 

 another. Howard records this migration in the city of 

 Washington on a dark, drizzly day in September as follows : 



"The army issued from the rear of an old restaurant 

 fronting upon Pennsylvania Avenue and marched across 

 the muddy street, undeterred by pools of water, ash heaps 

 and other barriers, directly south to the front of the 

 building opposite. 



" This building was a machine shop and at the direction 

 of the foreman several of the men took brooms and swept 

 back the advancing horde. They swept until their arms 

 were tired, but were unable to stem the advancing tide. 

 The foreman then directed that a line of hot ashes from 

 the furnace be laid along the brick sidewalk. This proved 

 an effective barricade. The foremost cockroaches burned 

 their antennae and their front legs and the army divided 

 to either side and scurried down into the area ways of 

 adjoining buildings in which they disappeared. The 

 march is said to have continued from two to three hours 

 and many thousands of the insects crossed in this way. 

 A moment's glance, after arriving at the spot, showed me 

 that the insect was the croton bug and that nearly all of 

 the individuals were females carrying egg-cases. 



"I called at the restaurant and found to my surprise 

 that no house cleaning had been going on and that no 

 special effort had been made by the application of insec- 

 ticides to rid the establishment of the roaches. 



" It seems then to have been a true migration, a develop- 

 ment of the true migrating habit in the croton-bug." 



Perhaps it is in this way, under cover of darkness, prob- 

 ably, that dwellings become suddenly infested with these 

 insects. 



