12 FARMERS’ BULLETIN 683. 
Among other methods for destroying the fleas in houses the fol- 
lowing have been tried and recommended: Scatter 5 pounds of flake 
naphthalene over the floor of an infested room and close tightly the 
doors and windows for 24 hours. After this time the naphthalene 
may be swept into another room, and so on, thus making the treat- 
ment inexpensive. The free use of alum, both in the powdered 
form sprinkled over carpets and rugs and by dipping papers in an 
alum solution and placing them under the rugs, is said to give satis- 
factory results. The fumigation of houses with sulphur fumes or 
hydrocyanic-acid gas also accomplishes complete destruction. In ad- 
dition to killing all of the fleas, rats and mice are destroyed by these 
last-mentioned methods. In using sulphur the infested building 
should be closed up tightly and the material used at the rate of 4 
pounds to each 1,000 cubic feet of space. If the immature stages have 
been destroyed by the methods mentioned above, 2 to 3 pounds of 
sulphur per 1,000 cubic feet of space will be sufficient to destroy the 
adults. The sulphur is made into a cone shape in a good-sized pan or 
kettle and placed in a larger pan containing water to avoid danger of 
fire from the heat generated. <A little alcohol is then poured into a 
depression made in the top of the cone of sulphur, and a match 
applied. Each room should have a pan of sulphur, and the rooms 
should be kept closed about 12 hours. As the gas generated corrodes 
metals and injures plants, it is necessary to remove metal objects and 
potted plants before fumigating. It is not advisable for anyone to 
undertake the use of hydrocyanic-acid gas without obtaining the com- 
plete directions for its employment as outlined in Farmers’ Bulletin 
699, entitled “ Hydrocyanic-Acid Gas Against Household Insects.” 
This gas is very poisonous, but is one of the most satisfactory for 
destroying all sorts of vermin in buildings. 
When house infestations are derived from fleas which breed be- 
neath or around houses the first step is to clean out all the loose 
material in which fleas may be breeding and burn it, and then to use 
crude petroleum freely about the breeding places. This may be fol- 
lowed by scattering common salt about and thoroughly wetting it 
down. The free use of lime on the cleaned areas also apparently de- 
stroys many immature fleas. In exceptional cases lawns become in- 
fested, and fleas breed out around the roots of the grass. It is im- 
practicable to apply chemicals in such situations, but much may be 
done to check the breeding by cutting the grass exceedingly short 
and thus exposing the voung fleas to the heat of the sun, which 
will usually accomplish their destruction. In certain sections it has 
been found feasible to destroy flea infestations in barns and hog runs 
by diking the infested areas and pumping water in so as to flood them 
entirely. 
