in Area IV at a burrow near Box 28 to which it 
had transferred its place of residence. The inter- 
esting thing about this observation was that im- 
mediately following release it made a long circuitous 
journey to its place of birth. 
In a sense the above and similar examples also 
provide information relating to the ability of rats 
to select alternate routes to goals. This ability to 
utilize alternate routes of travel is much better 
exemplified in those instances where rats, undis- 
turbed by the presence of the observer, have 
immediately selected an alternate route to a goal 
when they found their initial route blocked. Three 
examples of this commonly observed behavior are 
as follows: 
Example No. I (fig. 72B): Adolescent female No. 
48 on leaving Area I tried to enter Passage 2 but 
found the then dominant male No. 12 blocking the 
passage with its body. She then went back through 
Area I to Passage 1, crossed through the South 
Alley to Path 2, which she took toward the Food 
Pen. This rat was normally an inhabitant of Area 
II where she was born. The fact that she moved 
to the left on finding Passage 1 blocked is an indica- 
tion that she was responding to the structure of 
one of these similar Areas, even though it took her 
away from her own home. She nevertheless, 
appeared to realize her departure from her home 
since she took a detour through the South Alley to 
return to a more customary route of travel up 
Path 2. 
Example No. 2 (fig. 7 3 A): A camera on a tripod 
had been placed over some garbage nailed to a 
board at a position in front of Passage 1. The 
shutter was operated by a string from the tower 
outside the pen. Normally male No. 22 harbored 
in Area I and utilized Path I and Passage 1 on its 
trips to the Food Pen. Occasionally it harbored 
temporarily in the South Alley Burrow. This was 
the case during the late afternoon of July 7, 1948, 
when the camera setup was placed along his usual 
route of travel. He left the South Alley Burrow 
shortly after 4:30 p.m. and headed to the Food 
Pen via Passage 5. As he returned up Path 1 
toward Area I, he exhibited the strange object 
reaction by avoiding the new structure in its 
environment. This avoidance took him to and 
momentarily into the South Alley Burrow from 
which it proceeded to Passage 2, the alternate place 
of gaining access to Area I. Prior and later obser- 
vations showed that male No. 22 most regularly used 
Passage 1 in departing from Area I, although when 
the occasion demanded, he would immediately 
adjust to the use of Passage 2. 
Example No. 3 (fig. 73A): Female No. 75 who was 
in the 14th day of her first pregnancy made a num- 
ber of trips between 5:15 p.m. and 6:45 p.m. 
carrying food from the Food Pen via the West Alley 
and Passage 4. At 6:45 while on one of these trips 
through the West Alley she was attacked and chased 
by a larger female, who presumably was from the 
South Alley Burrow. On subsequent food storage 
trips, which began immediately after this encounter, 
she shifted her route of travel to Path 4. This shift 
to an alternate route is an example of the manner 
in which social action affects space utilization. 
Both of the above sets of examples offer con- 
siderable evidence that rats learn the trails about 
their environment with sufficient detail to enable 
them to make immediate adjustments of selection 
of alternate or circuitous routes of travel. One 
might also interpret them as suggesting a general 
position awareness with reference to all points in 
their environment, with which they have had 
experience, even though they are unable to per- 
ceive those points from the position in which they 
happen to be. This awareness seems to be more 
than just a knowledge of the patterns of existing 
trails, although this is extremely important. 
Certain observations give evidence of this aware- 
ness, whose properties fulfill the requisites of the 
“cognitive map” postulated by Tolman (72). 
Example No. 7 (fig. 72A): Female No. 44 was 
released headed into the West Alley near Path 1 
opposite the South Alley Burrow. The South 
Alley Burrow was the place of her birth. She 
initially ran for 5 feet northward in the direction 
she had been headed by the observer. She then 
turned around and headed back toward the South 
Alley Burrow, but upon reaching Path 1 she be- 
came startled by a movement of the observer, 
whereupon she headed up Path 1 and over into 
Area I. The initial change in direction of move- 
ment is interpreted as giving evidence of the 
position of the South Alley Burrow, which she 
could not perceive. This still involves the use of 
prior trails. 
Example No. 2 (fig. 73B): Male No. 34, which 
was caught at the southeast outside corner of the 
Food Pen, was released near its southeast outside 
corner. Upon release it wobbled about exhibiting 
considerable evidence of still being under the 
effects of anesthesia. Without utilizing trails 
at anytime it wandered over to the median barrier 
81 
