304 PESTS OF THE HOUSEHOLD AND STORED PRODUCTS 
the other water. Use four parts of flour to one part of plaster of 
Paris. Arrange the dishes so that roaches can easily climb on them and 
pass from one to the other. Badly infested buildings may be entirely 
cleared by fumigation with hydrocyanic acid gas. Great care should 
be taken in using this treatment, for it is violently poisonous. 
Fleas 
Fleas are too well known to need description. Where houses become 
infested, the trouble is nearly always traceable to a pet cat or dog, 
although the pest may be brought in on clothing of a visitor. The 
species usually observed is the common Cat 
and Dog Flea (Ctenocephalus canis Curt.). 
The adult flea lays eggs among the hairs of 
its animal host. These drop off, and the egg 
hatches to form a minute, white, slender larva, 
which lives in cracks in the floor or other pro- 
tected places, feeding on any available organic 
tae ; matter, such as hairs, or even dust. The 
ge haut ater larva transforms to a pupa, and later the adult 
and natural size. Orig- emerges, ready to leap on the first cat or dog 
inal. that comes its way, or on a human being. 
To rid a house of fleas all cracks must be washed with hot suds, and 
preferably dosed with gasoline. At the same time any animal pets 
must be looked after and cleared of the insect. Insect powder dusted 
thoroughly into the animal’s fur will stupefy the fleas and cause them 
to drop off. They may then be gathered up and destroyed. 
Another treatment is to scatter over the floor of a room 4 or 5 pounds 
of naphthaline, and keep the place tightly closed for 24 hours. This 
will effectually rid a room of the adult insects, but will not be likely to 
affect any eggs that might be present. The naphthaline may be swept 
up and used over again. 
The Bedbug (Cimezx lectularius Linn.) 
The bedbug is an ancient and cosmopolitan insect, existing through- 
out the world. It has become wholly domesticated, and lives entirely 
