144 
Psyche 
[September 
sweeping it into a broad mound in front of the opening. Mounds 
of completed nests measure from 8 to 13 cm in length by 6 to 8 cm 
in width and 0.5 to 1.5 cm in depth. No true leveling movements 
occur at any time, but mounds may weather away after several days, 
particularly if there has been a heavy rain or strong wind. 
Following completion of the burrow, but before making a cell 
or bringing in prey, the wasp digs a short, blind burrow on one 
side of the entranceway, sometimes one on each side. Whether these 
are dug before or after the initial closure of the true burrow was 
not determined. Thereafter these “false burrows” are never closed, 
but the true burrow is closed from the outside when the female 
is hunting, from the inside when she is inside the nest for more 
than brief periods. I obtained the impression that the wasps keep 
these false burrows “in repair”, although they do not use them in 
any way. One female was seen to bring a bee into the true burrow, 
then emerge and enter a false burrow for a moment and come out 
and fly off. 
I found no fresh nests without at least one false burrow. At 
Granby Center, N. Y., I took notes on four nests, three of which 
had one false burrow and one of which had two. These false 
burrows began 1-4 cm from the opening of the true burrow and 
started out at roughly a right angle to it, but often curved toward 
or away from the true burrow. They varied in length from 6.5 
to 9 cm, and for the most part were at only a 15 to 30° angle with 
the horizontal (like the beginning portion of the true burrows) 
(Fig. 1). 
In Lexington, Mass., I observed many nests with false burrows, 
but took measurements on only seven. Of the seven, four had one 
and three had two false burrows beside the entrance of the true 
burrow and forming a 45 to 90° angle with it ; these varied in length 
from 1 to 3 cm (notably less deep than those at Granby Center). 
In addition, four of these nests had additional, very shallow false 
burrows (0.5-1.0 cm deep), not beside the nest entrance but farther 
back on the mount. One nest had a total of five false burrows, one 
of them with a double entrance (Fig. 3). Such nests presented a 
confusing picture of holes going in various directions, with the true 
nest entrance well concealed and discoverable only when the female 
arrived with prey. 
Nest structure. — Diameter of both the true and false burrows is 
about 5 mm. As already mentioned, the top section of the true 
burrow is at only a 15 to 30° angle with the horizontal; after some 
8 to 1 5 cm the burrow bends down sharply, attaining an angle of from 
