EXTERNAL PARASITES 69 



numerous than the females. If conditions are favorable the eggs 

 hatch in from ten days to three weeks, and the lice live for a 

 considerable period, several months under favorable conditions. 

 During their development they moult frequently, sometimes as 

 often as ten times, becoming slightly darker with each molt. 



Lice breed with great rapidity; it has been computed that 

 the unhindered reproduction of a single pair would reach 

 the enormous total of 125,000 individuals in the third gen- 

 eration, which may mature in eight weeks! 



EFFECTS OF LOUSE INFESTATION 



Chicks hatched in the incubator are free from lice and 

 stay so until placed with lousy hens or chicks, or in quarters 

 infested by lice. Lice produce much irritation ; the effect 

 of large numbers upon birds is quite marked. The lousy 

 birds scratch, pick at the feathers, show signs of being drowsy, 

 may refuse to eat, and, in growing birds, development is re- 

 tarded. 



Young chicks infested Avith lice often sit around, moping, 

 with wings hanging down, and in a week or two may die. 

 For this reason brooder chicks sometimes thrive better, grow 

 faster, and are freer from certain lailmients than chicks 

 hatched by the hen. It has been said that lousy birds show^ 

 a greater tendency to wallow in the dust than those not in- 

 fested. 



The effect of lice upon older birds is not so severe as upon 

 younger ones, but is noted in conditions of flesh and in the 

 production of eggs. The irritation is sometimes so severe 

 that hens desert their iiests. Their combs may become dark 

 or black. Birds unable to rest day or night become emaci- 

 ated and die. 



To find the lice, part the feathers and the lice will be 

 found running over the skin or base of the feathers. A 

 favorite location for lice is around the vent, where the tem- 

 perature is warm; but they may be found on any part of 

 the body and at all seasons of the year, but are most com- 

 mon in' the hottest months of the year, July and August. 

 During these months conditions are more favorable for their 

 propagation. 



DEALING WITH LOUSE INFESTATION 



A time-honored and very effective method of treating young 

 chicks for lice is to grease the head and neck, under the 

 wings and around the vent. Blue ointment, lard and sul- 

 phur, salt and butter, and various other greases are used, 

 but none is more effective than lard alone, which, although 



