320 NATURAL INCUBATION AND BROODING 



exceptionally hot weather in the summer or late spring, it is well 

 to leave an open pan or low bucket on the ground, so that, when 

 the birds desire, they can immerse their plumage in the water. 



Cleanliness in the sitting coop or nest is of paramount import- 

 ance, since it means the prevention of vermin, improved health 

 of the hen, and more ideal conditions for the chicks. Three points 

 should be here considered : (1) The droppings should be frequently 

 removed, as well as any cracked shells or extremely dirty litter. 

 This can best be done when the birds are off the nest to eat. (2) 

 An abundance of dust should be provided in a box within easy 

 access of the nest, so that the sitting hens can dust themselves, 

 which is just as essential to them as a bath is to human beings, 

 and it also helps to keep away body lice and mites. (3) The neces- 

 sity of dusting the hen with a good insect powder once or twice 

 during the incubation period. The most convenient times are on 

 the seventh and fourteenth days when the eggs are tested. 



Testing the Eggs. In order to determine the fertility of the 

 eggs and the development of the embryo, which is the gauge of 

 the efficiency of the hatch, it is advisable to candle eggs at least 

 once, and probably twice, during the hatch. This process is 

 described in the following chapter (p. 343). 



Take out all which will not hatch, thus enabling the hen to 

 better cover the remaining eggs. Or, when fertility is rather low 

 and two or more hens are sitting, take the fertile eggs from one 

 hen and put them under others. If the eggs are tested twice dur- 

 ing the hatch, the most convenient times will be on the seventh 

 and fourteenth days. In natural incubation it may be best to 

 test but once, since testing has a tendency to disturb the hen 

 more than some consider advisable. 



Importance of Keeping Sitting Records. In natural incuba- 

 tion, records should be kept of each sitting hen, in order to ascer- 

 tain just how the hatches are running and to perfect the method. 

 Such records should state the number of the nest, the breed of the 

 hen, the date when set, the variety or kind of eggs, the day of first 

 test, and the number of fertile, infertile, and dead germs, also the 

 date of second test, giving the number of fertile and dead germs. 

 The percentage of hatch, or the number of live chicks taken from 

 the nest, should also be stated. This record may be kept on cards 

 in a rack above the nest or in a book. Such a record will show the 

 keeper when his hens are due to hatch, when fertility is running 

 low, and perhaps enable him to make a pedigree hatch. 



