External Parasites 215 



duce very rapidly, especially in spring and summer. The 

 eggs are laid in concealed places, usually in cracks containing 

 filth or in dirty nesting material. The young mites are 

 white and have only 6 legs. Their first food is probably 

 filth or decayed wood. They molt several times and their 

 cast skins are often seen as a white powder on the perches. 

 After the first molt the larvae have 8 legs. The mites are 

 able to live and reproduce for months at least without ani- 

 mal food, but when they are associated with fowls the older 

 larvae and adults depend upon the blood of the fowls for 

 food. They usually attack the birds at night but sometimes 

 are found feeding on laying or brooding hens during the 

 day. They pierce the skin with their needle-like jaws and 

 suck the blood. The irritation due to the biting of a number 

 of these creatures disturbs the rest of the bird and the loss of 

 blood may be considerable. The mites thrive best in dark, 

 damp, dirty houses and may be found in such houses for 

 months after all fowls have been removed. They will bite 

 man or other mammals, causing severe irritation, but do 

 not remain on strange hosts for any length of time. Fowls 

 should not be allowed to roost in sheds with other animals, 

 as the sheds may become infested with the mites which 

 will disturb the other animals as well as the fowls. 



Diagnosis. — If the birds are not doing well, especially if 

 they appear emaciated and dejected, they should be exam- 

 ined at night for mites. In the daytime the ends and 

 under sides of the roosts and the cracks in them should be 

 examined. Numbers of the mites are often found by pry- 

 ing up a loose cleat or splitting off a wide loose sliver. They 

 may often be found in old straw nests. 



Treatment. — Clean, dry, well ventilated houses which get 

 plenty of sunlight are seldom badly infested. The first 

 step in eradicating or controlling the pest is thoroughly to 

 clean the houses. Remove the droppings and all the old 



