1928] Modification of Nest-Building Habits of Polistes 
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MODIFICATION OF THE NEST-BUILDING HABITS 
OF POLISTES. 
By Phil Rau, 
Kirkwood, Mo. 
The shape of the nests of Polistes is not determined by the 
iron-clad instincts of the builders. Under pressure of emergency, 
Polistes builds cell upon cell, regardless of the shape of the nest 
as a whole. One often finds elongated nests of P. pallipes (fig. 1.) 
that have been built in the space between two boards in a shed. 
The builder is obliged, if she is to use the chosen location, either 
to limit the size of her nest or modify it; she has proven herself 
capable of adapting her handiwork to new requirements. 
Figures 2 and 3 show two nests of the same species, P. 
pallipes, that were built in the narrow space behind closed 
shutters; one was on an old building at Creve Coeur Lake, Mo. 
and the other at Clifton Terrace, 111. In the nest in figure 2 
where horizontal expansion was impossible, the wasps built a 
sky-scraper, piling tier upon tier of cells, all of these slanting 
upward toward the horizontal, whereas the normal cells fall ver- 
tically. The nest, illustrated in fig. 3, likewise adapted to narrow 
space, shows the same tendency in construction, but in this case 
some of the cells slant sufficiently toward the vertical to show 
that the workers were trying to give the larvae homes which nearly 
approached the normal position. A third such nest had a dozen 
large cells built horizontally in a haphazard way on top. 
Not only in P. pallipes do we see such digressions, but in P. 
annularis also. I have examined two large nests of P. annularis, 
where I found from three to five cells that were being fashioned 
about the roof at the base of the petiole. These, however, were 
not large, and in all probability merely showed the building 
instinct misdirected, i. e. the workers were probably adding paper 
pulp to strengthen the petiole and so far forgot themselves as to 
fashion cells at the wrong place. “Gross ist die Macht der 
Gewohnheit.” Certainly P. annularis, in extending her nest, 
