only a hundred yards from my house. I am cer- 
tainly indebted to him for this consideration. 
Without the close proximity of the study area to 
my place of dwelling it would have been impos- 
sible to conduct effectively this study which re- 
quired such irregular hours. 
During the initial phases of the study consider- 
able difficulty was met in constructing recorders, 
which would efficiently record each time a rat 
passed by. This was finally solved through the 
donation of four electronic rattraps by the L. F. C. 
Corporation of New York City. The circuits of 
these were modified to eliminate the electrocuting 
mechanism. Then, whenever a rat passed through 
the beam of light projected on the photoelectric 
cell, a circuit was completed which activated a pen 
on a tape recorder. 
During April and May of 1949 the U.S. Army 
Signal Corps made available a photographic crew 
and the necessary accompanying facilities for the 
detailed filming of the behavior of the rat. Major 
W. C. Lown had supervisory control of the general 
operations, while Lt. Strickland directed the actual 
field operations. The crew consisted of six movie 
camera operators, one still photographer, one 
sound technician, two electricians and two prop 
men. The immediate purpose of these films was 
to obtain certain desired footage for its integration 
in a series of films on the biology, control, and 
epidemiology of the rat which was being jointly 
prepared by the U.S. Army and the U.S. Public 
Health Service. However, the facilities of the 
camera crews were made available for the recording 
of all obtainable details of the activities of the rats, 
irrespective of their use in the projected series of 
films. I have had the opportunity of examining 
this extensive footage frame by frame. This de- 
tailed examination has been a greatly facilitated 
proper interpretation of rat behavior. I am 
indebted to the Signal Corps for making available 
for this publication several of the included still 
photographs. 
14 
