have finished feeding and begin to migrate, crawl out of the manure,
drop into the water below, and are drowned. Each week the plug is
removed from the pipe, and all the maggots are washed into the cistern.
The floor is then cleaned of any solid particles by means of a
long-handled stable broom or by a strong stream of water from a hose.
The pipe being again plugged, the floor is again partly filled with
water and the trap is ready for another week's catch. A platform of this
size will hold the manure accumulating from four horses during the
period of four months, or about 20 days' accumulation from 25 horses, if
the heap is well built and made at least 5 feet high.

[Illustration: FIG. 9. A maggot trap for house-fly control. View showing
the concrete basin containing water in which larvæ are drowned, and the
wooden platform on which manure is heaped. (Hutchison.)]

Experience with this maggot trap clearly indicates that best results can
be secured if the manure is compactly heaped on the platform and kept
thoroughly moistened. It is best to apply a small amount of water each
morning after the stable cleanings have been added to the pile. It
should be borne in mind that in order to make this trap a success the
platform beneath the pile must be kept comparatively free of
accumulations of manure, and moisture applied regularly to drive the
maggots out.


COMPACT HEAPING OF MANURE.

Another method of disposing of manure has been recommended by English
writers. The manure is built up in a compact rectangular heap, the sides
of which are beaten hard with shovels. The ground around the edges of