110 PRINCIPLES OF POULTRY-HOUSE CONSTRUCTION 
houses than small- or close-comb breeds. Birds of low vitality 
with poor circulation will be much more liable to freeze their 
combs than those of high vitality. A cold, damp atmosphere will 
do more damage than a cold, dry:atmosphere. The house should 
be so arranged that the temperature of the birds’ bodies may be 
conserved. At night during very cold weather the use of muslin 
drop-curtains in front of the perches is sometimes helpful. 
Any arrangement which will make it possible to cool the house 
off during the hot summer nights will be very desirable. One 
method used is to provide a small hinged opening in the back of 
the house which when open allows the air to circulate freely 
between the ceiling and roof over the roosting quarters. 
Rats and Mice——The house should be built, as nearly as pos- 
sible, to be proof against rats and mice. These enemies are often 
a source of great loss. The cost of a good concrete floor will often 
be saved in one year by keeping out rats. The protection against 
rats affords great saving in the feed bill, for a family of full-grown 
rats will eat or waste as much dry mash as a flock of twenty-five 
laying hens. 
Sanitation —The internal construction of the house should be 
as plain as possible. If matched lumber is used, it offers less 
hiding-places for bacteria, lice, and mites, so that a spraying with 
a good disinfecting solution will reach all possible hiding places. 
All internal fixtures, such as nests and perches, should be made 
movable, so that they can be taken out of the house and thoroughly 
cleaned and disinfected. 
Size and Type of House.—The exact form of house has a 
definite influence on the cost of construction. The type selected 
will be determined by the number of birds to be kept and by the 
character of the land upon which it is to be located. The small 
colony house costs more for its capacity than the continuous 
house. In the latter a light door or muslin partition answers for 
two outside end walls. Aside from the importance of economy of 
construction, the colony house is colder, having more surface 
exposed to the varying weather conditions, and more labor is 
required to care for the birds kept in them. The larger the house 
and the larger the flock, the less will be the cost per bird for 
shelter and labor in caring for them. There are three different 
designs into which all types of poultry houses might logically be 
grouped: (1) The small single-pen colony house. (2) The long, 
continuous house of two or more pens. (3) The large single-unit 
