1964] 
Creighton — Habits of Pheidole 
171 
the environmental conditions are extreme enough to tax the hardiest 
xerophiles. This is shown by the fact that few of them can survive 
in these areas. Competition for food in such areas is severe and con- 
siderable advantage must derive from a type of nest that no predator 
could enter except through a fixed and easily guarded opening. 
As soon as the nests of clydei were found, observations were be- 
gun on its foraging activities. The observations were made in late 
March and early April. At that time the ants were foraging mainly 
in the period between 9:00 A. M. and 1 :00 P. M. The nests were 
in shade until 8 130 A. M. but there was a thirty minute period after 
the sunlight reached them when no foragers emerged. About 1 :00 
P. M. foragers ceased to emerge from the nest but during the next 
hour or so many foragers returned to it. Observations made after 
dark showed nothing that could be regarded as foraging, although 
minors could be brought out of the nest if the entrance was sufficient- 
ly illuminated. It appears that all the foraging is done by the minors. 
The majors leave the nest only to assist the minors in dealing with 
some large item of food when this has been brought close to the nest 
entrance. While the minors obviously follow scent trails they do not 
forage in columns for the foragers are well separated. Except for 
one minor, who brought in the withered anther of a flower, all 
material brought to the nest during the period of observation con- 
sisted of arthropods or their disarticulated remains. Much of this 
was too fragmentary for identification but on several occasions entire 
arthropods were brought in. There were two dead spiders, two dead 
majors of Ph. grallipes, one dead fly, one dead geometrid larva and 
one living termite nymph. No seeds were ever brought in, although 
there were a number of plants in the area which had gone to seed. 
On the basis of these observations it may be concluded that clydei is 
not a harvester but carnivorous. But, like many xerophiles, it appears 
to be an opportunist where food is concerned. Since the only way to 
get the ants out of the nest was to bait them out and since I wished 
to set up artificial nests, I spent considerable time at first looking for 
suitable insect bait. Later I discovered that sugar cookies or cheese 
crackers worked just as well. On one occasion a bit of sugar cookie 
about the size of a quarter was inadvertently left at the entrance of 
one of the nests at the conclusion of the observations. The fol- 
lowing day there was no trace of it and the members of the colony 
which had acquired this prize were so full or so busy with their bits 
of cookie that they did not begin foraging again until the next day. 
As already noted the major of clydei has a secondary role in for- 
aging activities. When entire arthropods are brought in by the minors 
