in such a manner that no water will be retained, 
thus eliminating one source of mosquito breeding 
in the community. 
Screening is still a very important measure for 
keeping flies and mosquitoes out of buildings. All 
windows, doors, and other openings should be 
adequately screened, and damaged screens should 
be promptly repaired. Where the use of screen doors 
is impractical, such as in some commercial estab- 
lishments, fans over the doorway on the inside may 
create a current of air through which few flies will 
pass. When screen doors are used, they should be 
equipped with self-closing devices. The screening 
of outside water containers, such as rain barrels, 
will help prevent mosquito breeding. 
Food processing plants in urban and rural areas 
should provide sanitary disposal of all putrescible 
waste. Improper handling of this material from can- 
neries, abattoirs, and crab and oyster packing 
plants frequently contribute to high insect and 
rodent populations, which in turn endanger the 
health and welfare of workers and nearby residents 
and increase the possibility of contamination of the 
food products. 
The practice of throwing bread and other foods 
outdoors for birds may create a rodent problem. 
Bird lovers should use hanging feeding cages or 
platforms. 
All possible efforts should be made to elimi- 
nate the outdoor privy, which is generally the 
source of an appreciable portion of the fly popula- 
tion in a given area. Rat burrows are frequently 
found in the immediate vicinity of privies, too. 
Since flies have been proven to be important 
carriers of diarrhea-dysentery diseases, every 
effort should be made to extend sewers and to 
eliminate privies. If public sewers cannot be made 
available to a given area within a reasonable time, 
the use of septic tanks with absorption fields 
should be encouraged. 
SANITATION AS RELATED 
TO INSECT AND RODENT CONTROL 
IN BUSINESS, INDUSTRIAL AND 
INSTITUTIONAL ESTABLISHMENTS 
Much of the material presented in the preceding 
sections has definite applications to business, 
industrial, and institutional establishments. How- 
ever, certain types of establishments have charac- 
teristics that present sanitation problems related 
to insect and rodent control not found in other 
situations. Some examples of these are presented 
here. 
Each category of industrial activity has its own 
insect and rodent problems. Most of these result 
from operational procedures and material-storage 
practices, building structure, equipment and its 
location, lack of maintenance, improper house- 
keeping including inadequate storage and disposal 
of putrescible wastes. 
Food processing plants frequently have infesta- 
tions of rodents and insects whose presence leads 
to contamination or adulteration. In the control of 
insects, cleanliness of the whole plant is especi- 
ally important. The floors, walls and ceilings 
should be kept scrupulously clean. The processing 
machinery should receive special attention, since 
it often becomes ht ^vily infested with insects 
when cleaning is inadequate. 
The cleaning of the floors and walls may be 
difficult because of cracks, crevices, and small 
holes. These can hold food particles attractive to 
both insects and rodents and can also provide 
ways for insects to enter and leave rooms and 
buildings. The use of a caulking compound or other 
36 
