FLEAS AKI) THEIR CONTROL. 13 



and mice. When sulphur is to be employed 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, 2 to -i pounds of sul- 

 phur per 1,000 cubic feet of space will be sufficient to destroy the 

 adults. The sulphur is made into a cone-shaped mass in a good-sized 

 pan or kettle and placed in a larger pan containing water to avoid 

 danger of fire from the heat generated. As sulphur will not burn 

 readily at first a little alcohol is poured into a depression made in 

 the top of the cone, 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 from burning sulphur corrodes metals and in- 

 jures plants, it is necessary to remove metal objects and potted plants 

 before fumigation. It is not advisable for anyone to undertake the 

 use of hydrocyanic-acid gas without obtaining the complete direc- 

 tions for its employment contained in Farmers' Bulletin 699, entitled 

 "Hydrocyanic-Acid Gas Against Household Insects." This gas is 

 very poisonous, but it 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. Then common 

 salt should be scattered about and thoroughly wet down. A second 

 wetting two or three days later usually will accomplish complete 

 destruction, but if this is not found sufficient, one or two additional 

 wettings may be given. Where crude petroleum is cheap and espe- 

 cially where water can not be applied easily, sprinkling the gi'ound 

 with a liberal amount of this oil will give good results. The free 

 use of lime on the cleaned areas also apparently destroys many im- 

 mature fleas. In exceptional cases lawns become infested, and fleas 

 breed out around the roots of the gi^ass. It is impracticable 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 young fleas to the heat of the sim, 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 in- 

 fested areas and pumping water in so as to flood them entirely. 



TRAPPING FLEAS. 



Following the treatment of host animals and the thorough clean- 

 ing up of the premises, as has been outlined, many of the remaining 

 adult fleas may be caught by the use of traps. 



There seems to be some virtue in the use of lights at night for at- 

 tracting the adult fleas. A small lamp set in a pan of water covered 

 with a film of kerosene may be used for this purpose. 



