HOUSE FLIES. 4.3 
Flies have been found to breed in surprising numbers in small 
accumulations of material in the corners of feed troughs and mangers, 
and it is important that such places be kept clean. 
FLY-TIGHT MANURE PITS OR BINS. 
The Bureau of Entomology has for some years advised that 
manure from horse stables be kept in fly-tight pits or bins. Such 
pits can be built in or attached to the stable so that manure can be 
easily thrown in at the time of cleaning and so constructed that the 
manure can be readily removed. The essential point is that flies be 
prevented from reaching the manure, and for this reason the pit 
or bin must be tightly constructed and the lid kept closed except 
when the manure is being thrown in or removed. There is no doubt 
as to the effectiveness of this method when the necessary precautions 
are taken, especially if the manure is removed at frequent intervals. 
FREQUENCY WITH WHICH MANURE SHOULD BE REMOVED. 
Another point must be considered in deciding the question as to 
how often the manure should be removed. In this connection it 
should be borne in mind that when the larve have finished feeding, 
they will often leave the manure and pupate in the ground below 
or crawl some distance away to pupate in débris under boards or 
stones and the lke. Hence the manure should be removed before 
the larve reach the migratory stage; that is to say, removal is neces- 
sary every three days, and certainly not less frequently than twice 
per week during the summer months. <A series of orders issued in 
1906 by the Health Department of the District of Columbia, on the 
authority of the Commissioners of the District, covers most of these 
points, and these orders, which may well serve as a model to other 
communities desiring to undertake similar measures, may be briefly 
condensed as follows: 
HEALTH OFFICE REGULATIONS FOR CONTROL OF HOUSE FLIES IN CITIES. 
All stalls in which animals are kept shall have the surface of the 
ground covered with a water-tight floor. Every person occupying 
a building where domestic animals are kept shall maintain in con- 
nection therewith a bin or pit for the reception of manure and, 
pending the removal from the premises of the manure from the 
animal or animals, shall place such manure in said bin or pit. This 
bin shall be so constructed as to exclude rain water and shall in 
all other respects be water-tight, except as it may be connected with 
the public sewer. It shall be provided with a suitable cover and 
constructed so as to prevent the ingress and egress of flies. No per- 
son owning a stable shall keep any manure or permit any manure 
to be kept in or upon any portion of the premises other than the bin 
