10 BULLETIN 553, U. S. DEPARTMENT OF AGRICULTURE. 
daylight. The writer finds that normal feeding takes place during 
the hours of darkness and that mites leave the fowl soon after 
feeding. All stages of mites will go on a fowl. feed, and leave it in 
less than two hours. In another experiment from 20 minutes to one- 
half hour was found to be sufficient time for complete engorgement. 
In one experiment about 30 per cent of a large number of mites put on 
a fowl in an earthen jar at 10 a. m. were full fed when observed at 
'2 p. m. The fact that some mites will feed day or night accounts in 
part for their very rapid increase about a sitting hen. 
Though mites feed at night, they do not necessarily all crawl off 
the host before the fowls leave the roost. Both fed and unfed mites 
may be retained in the feathers when the fowls are running about. 
The number of such mites on a fowl seems to be small, but quite suffi- 
cient to infest a new place. The length of time mites may remain on 
a fowl after it has been on an infested roost is not certain. Experi- 
ments designed to throw some light on this point developed that 
nearly all mites leave the fowl by the end of the third night, but a 
few stragglers may persist for several days. It would be advisable 
for a person introducing new stock into his mite-free flock to use a 
little caution if he would avoid an infestation. 
The author would suggest that new stock not known to be free of 
mites be allowed to roost the first few nights on a new roost wrapped 
with pieces of folded paper, preferably black. The object of using 
the paper is to furnish a convenient place for mites to hide. The 
paper may be examined, and if mites are found the fowls should be 
kept on this roost five or six days, or until no more mites come off of 
the fowls. If mites are discovered, by removing and destroying the 
papers and treating the roost thoroughly with kerosene or crude oil 
any danger of the mites getting back on the fowls can be avoided. 
The ease with which mites reach the host has a decided bearing on 
the rapidity of increase. Hungry mites, though placed quite near a 
fowl, have great difficulty in finding the host unless the means of 
access is direct. This fact would account for the mite preferring 
to hide on the roost. When mites are found all over the walls the 
infestation must be a heavy one. To apply the above facts to aid in 
control work, the roosts should not be connected up with the walls 
of the chicken house unless some method of preventing the access of 
the mite to its host is used. The same may be said of the nests. The 
simpler and more isolated the roosts and ne<ts. the easier it will be 
to eradicate the mite. (For control measures see Farmers* Bulle- 
tin 801.) 
HIDING HABITS. 
The direct rays of the sun act as a powerful killing agent when 
mites are exposed to them. Mites put on a board in the direct sun 
(July) were killed in a few seconds. Need of a suitable dark, pro- 
