(1) _Different species._ There are at least six different species of lice that attack pigeons in this country. The three most common are— (_a_) _Feather louse._ This is the long, slender species that lives on the barbs and shaft of the feather over nearly any part of the bird’s body. (_b_) _Golden feather louse._ This louse is a little shorter and much broader and lives on the feathers, particularly on the bird’s body. (_c_) _Body louse._ This is the largest of the pigeon lice. It lives on the skin rather than on the feathers. It is thought that these lice, by biting the very young pin feathers when they are filled with blood, cause the small pinhole perforations often seen in pigeon feathers. [Illustration: _Figure 41. Life cycle of pigeon lice._ TL70210] (2) _Habits_ (fig. 41). In order to combat lice properly and intelligently, it is necessary to know something about where and how they feed, live, and breed. (_a_) Adult lice live on the skin and feathers of the bird and only rarely leave the pigeon. When accidentally dislodged, they crawl very short distances to other birds. Lice cannot live longer than a few days away from the birds. (_b_) Lice eat bits of feathers, scales, and other debris off the skin. They do not suck blood. (_c_) Female lice lay eggs (nits) along the shafts of the feathers, particularly on the primary coverts. (_d_) Louse eggs hatch in 10 to 14 days. (_e_) Young lice eat, molt (3 to 5 times), and grow to maturity in about 14 days. (3) _Diagnosis._ Infested pigeons are restless and constantly pick and scratch in an effort to dislodge the lice. Heavily infested birds may become weak and thin because the constant annoying movement of lice interferes with their proper relaxation and rest. Careful examination of the birds will reveal the lice. [Illustration: _Figure 42. Life cycle of common red mite._ TL70211] (4) _Treatment._ The use of sodium fluoride is a good standard method for ridding pigeons of lice. It can be applied in two ways: (_a_) _Dip method_ is very efficient, but can be used only in warm weather. Birds should be dipped on a warm, sunny day early enough so they will dry before night. Each bird is immersed into the solution up to the head, and the feathers ruffled to allow penetration of the solution. Then the mouth and nostrils are held shut and the head immersed. The dip is made of 1 gallon warm water, and 1 ounce sodium fluoride. (_b_) _Dust method_ may be used at any time. The birds are held while a few pinches of powdered sodium fluoride are dusted into the feathers over various parts of the body. Sodium fluoride poisons lice when they eat it. Efficiency in delousing birds depends on thoroughness of wetting or dusting. (5) _Repeat treatment._ Neither method above will kill nits nor prevent them from hatching; therefore, the delousing must be repeated in 10 to 14 days in order to kill newly hatched lice.