proof the building. ‘This is: true where the bats infest do 
between roof and ceiling, or other boxed=in: places easily reached fro 
ae difficult of sous pe the outsides The most effective repellent | 
To aac bitte out oe a ce by a repellent i 
from any drug store. The mabe Bees, dislike the gas given ‘off by ae naph ti 
see and will leave the roost: in ee dayiis ne NEU a few minut tes after it 
to Bn from an old eal ished roost, and aie ne of their cheeeee age 
istic odor is likely to attract other bats. Yor this reason bat—proofing, though more — 
difficult, is a much more desirable control method than the use of the naphthalene. 
DESTROYING BATS 
Killing the bats by fumigation is possible, although there are serious obje 
tions to the use of a poison gas in an occupied dwelling, and this method is no a 
recommended except as a last resort, after other means have failed, Destruction 
of the bats is usually undertaken ae bat~-proofing is impracticable because o 
the cost and the difficulty of reaching some of the roosting places with a repe 
lent. This conditien means that it will not be possible to reach and remove the 
carcasses, the decomposition of which will for a time add to the obnoxious odors 
aeehesated with a bat roost. It also means that the openings through which the — 
bats had gained entrance to their roost must remain open, and then the character 
istic bat odor will long remain an invitation te other bats to reestablish the 
roost. 
can be generated and applied by several Menneds: Tt-3s highly effective, but 2s ; 
it is also extremely poisonous to human beings, it should not be used without 
full knowledge of the dangers involved and of the precautions to be taken. © 
When spaces between walls are wepeeed by bats, they can often be reaenaee 
from the outside by loosening boards or siding or by boring a hole with a brace 
and bit. Into such openings the nozzle of a dust pump may be inserted and clei — 
cyanide dust blown into the cavity. Calcium cyanide rapidly generates yonseyeee > 
acid gas by combining with the moisture in the air. The quantity of dust needed © . 
will-depend on the size of the cavity to be filled, but in the average residence a : 
pound or two of dust will usually be ample for treating small enclosed spaces between ‘ 
‘double walls and between a ceiling and the floor above. The dust-pump method ~ 
should not be used from the inside, The house should be vacated before ealiatnn t 
cyanide is used and should not: again be’ entered until it has been aired for 
‘Several hours after the gassing. 
In many cases the more practical treatment would be to fumigate the entire E. 
attic, or even the entire building, which would allow the’ gas to penetrate into ~ 
all openings and insure the destruction of all animal life in the building, Far 
mers' Bulletin 1670, Hydrocyanic Acid Gas as a Fumigant, issued by the United a 
States Department of Agriculture, gives full instructions for fumigating build — q 
ings for. destroying household insects, and the procedure recommended is also : 
applicable in the destruction of bats. In general, when fumigation for destroy—— 
ing bats is found necessary, the work should be entrusted to an experienced opera 
