128 INTELLIGENT BEHAVIOUR 
here,” writes Dr. Peckham,* “must be told the story of one 
little wasp whose individuality stands out in our minds more 
distinctly than that of any of the others. In filling up her 
nest she put her head down into it and bit away the loose 
earth from the sides, letting it fall to the bottom of the 
burrow, and then, after a quantity had accumulated, jammed 
it down with her head. Earth was then brought from the 
outside and pressed in, and then more was bitten from the 
sides. When, at last, the filling was level with the ground, 
she brought a quantity of fine grains of dirt to the spot, and, 
picking up a small pebble in her mandibles, used it as a 
hammer in pounding them down with rapid strokes, thus 
making this spot as hard and firm as the surrounding surface. 
Before we could recover from our astonishment at this per- 
formance she had dropped her stone and was bringing more 
earth, and in a moment we saw her pick up the pebble and 
again pound the earth into place with it. Once more the 
whole process was repeated, and then the little creature flew 
away.” 
Here we have intelligent behaviour rising to a level to 
which some would apply the term rational. For the act may 
be held to afford evidence of the perception of the relation 
of the means employed to an end to be attained, and some 
general conception of purpose. In this section, which deals 
with description of behaviour based on observation, the 
psychological explanation cannot be discussed. Similar in- 
dications of deliberate action may be held to be afforded by 
the sometimes elaborate “ locality studies” which these insects 
seem to make,—by the “ care that is taken by wasps to acquaint 
themselves with the surroundings of their nests.” A Sphez, 
for example, which had partially made and then abandoned 
several nests, left them without any locality study ; but when 
she had completed a nest in a suitable spot she made “a most 
thorough and systematic study of the surroundings. She flew 
in and out among the plants, first in narrow circles near the 
surface of the ground, and then in wider and wider ones as 
* Op, cit., p. 22, 
