216 THE HOUSE FLY—DISEASE CARRIER 
on cool nights, he bases another line of attack, which 
is to make a hole in the window screen, with the guid¬ 
ing strips outside and the trap inside, thus catching 
all the flies that attempt to enter the kitchen in that 
way. He has tested this device, but thinks that it can¬ 
not compete with the garbage-can trap. 
Professor Hodge (1910) points out that there is 
much yet to be known about the biology of the adult 
typhoid fly, its favorite foods, its needs for water, its 
habits in seeking shelter, length of life, and the dis¬ 
tance it flies, but he thinks that what little we know 
indicates that the strategic point of attack is the adult. 
He states that we have been long working on this 
theory unintelligently and ineffectively with sticky or 
poisonous fly paper and traps, but that these means 
have been employed only to kill the comparatively few 
flies that gain entrance to our houses. 
“Carry the war into Africa; develop the means of 
attack seriously and effectively in the out-of-doors, and 
I fully believe that there will be no filth flies to go 
back to the compost heaps and barnyards to lay their 
eggs.” After using his traps for a period, he found it 
possible to dine on the porch; as he expressed it, he 
had turned the tables on the flies, and put them in a 
prison and let himself out. Hodge wishes to stimulate 
invention towards making effective out-of-doors fly 
traps, and he urges experiments with different baits. 
He states that he did enough in the summer of 1910 
to be convinced that any country home “a half mile 
away from its nearest ignorant neighbor, or any town- 
