INTELLIGENT BEHAVIOUR IN INSECTS 127 
selected a new place, and began to dig again. This hole was 
also filled in ; she looked once more at the spider, and started 
a nest ina new place. This, in turn, was soon abandoned, as 
was a fourth. The fifth beginning was made under a leaf 
that lay close to the ground, but after twenty minutes’ work 
this place also was abandoned and a sixth started. ‘This, how- 
ever, was the final choice, and after forty-five minutes spent in 
digging it was completed.” 
This description shows an amount of apparent fastidious- 
ness which is quite irreconcilable with the hypothesis that the 
behaviour is merely instinctive. Not less fastidious are some 
wasps in the temporary closure of the hole with a stone or 
pellet of earth, the operation being repeated several times 
Fra. 19.—Solitary Wasp using a stone to beat down the earth 
over its nest (after Peckham). 
with different covers before the insect seems to be satisfied ; 
while in other cases the hole is hidden by bringing earth 
in such quantity as to render the place indistinguishable 
from the rest of the field. But in one case observed by Dr. 
Peckham, intelligent procedure was carried so far as ap- 
parently to involve the use of a tool, the same behaviour 
having been independently observed in the same genus (Am- 
mophila) by Dr. 8. W. Williston of Kansas University. ‘Just 
