trees. Many still do, but others have found attics, spaces between 

 building walls, and unused areas in upper stories much to their 

 liking. This habit constitutes the major objection to their presence. 

 From the droppings and urine deposited about the roost comes a 

 highly objectionable odor that is characteristic of bat roosting 

 places. This odor persists for a long time after the roost is 

 broken up and may serve to attract new colonies if preventive 

 measures are not taken. The noises created by crawling bats are 

 also disturbing to the householder. While they cause no actual 

 damage to structures, their presence in a dwelling is usually 

 undesirable. Exclusion or elimination is then necessary. 



CONTROL METHODS 



Repellents ; Frequently control can be accomplished by the use of 

 repellents. Bats dislike the odor of naphthalene and paradichloro- 

 benzine, two chemicals commonly used as moth and insect repellents. 

 When the roost is located in attics or other closed spaces that can 

 be reached easily, either of these materials can be used to drive 

 them out. Three to five pounds of naphthalene flakes will usually 

 be sufficient to treat the average attic. Simply sprinkle the 

 material liberally over the entire area. So objectionable is this 

 odor to bats that they will usually leave the roost within a short 

 time after it is introduced, even in broad daylight. Both of the 

 cheirdcals dissipate rapidly on contact with air, however, and appli- 

 cations may have to be repeated if no other control is practiced. 

 Bats are quite persistent, and it is often difficult to dislodge 

 them from old established roosts. Then too, new individuals may 

 be attracted by the odors left by departed guests. For these 

 reasons, bat-proofing should be considered a necessary adjunct 

 to the use of repellents. 



Bat-Proofing Buildings : Bats may enter buildings through large or 

 even small openings, such as unprotected louvres or vents, broken 

 windows, or other open spaces, or through old worn sidings, around 

 eaves, or cornices. The smaller species of bats can crawl through 

 an opening as narrow as 3/8 of an inch. It is necessary, therefore, 

 to eliminate all possible entrances. 



The larger openings should be covered with sheet metal 

 or with l/li-inch mesh hardware cloth if ventilation is necessary. 

 It is essential that no openings larger than l/U-inch are left. 

 In the case of narrow cracks, they are best plugged with oakum, 

 tow, or similar packing material, and sealed with caulking compound. 

 This will provide useful weather protection as well. Inspect care- 

 fully all old siding and baseboards to make certain that alternate 

 entrances have not been overlooked. 



