1960 ] 
Creighton — Pheidole militicida 
3 
he found others in the vicinity of Portal, Arizona. Thei information 
concerning the exact site of the latter colonies, which Dr. Cole 
obligingly furnished, was a notable help to this study and we wish 
to express our thanks for it. 
While the observations just cited added to our knowledge of 
militicida , none of them could furnish information on winter condi- 
tions in the nests of this species. Thus when Creighton and Gregg 
reviewed Wheeler’s hypothesis in 1955 (2), they could do little more 
than point out the improbability of his explanation. Although it 
was clear that a number of southwestern species of Pheidole , which 
have majors with unusually large heads, showed none of the habits 
predicted by Wheeler, it was still possible that he might have been 
right in the case of militicida. Positive proof that Wheeler’s account 
of the habits of militicida is incorrect was secured by the writers 
in the winter of 1959. During that winter we had fifteen colonies of 
militicida under field observation on all but a few days. Living 
majors were taken from thirteen of these colonies during the period 
between January 8th and March 3rd. Our original attempts to se- 
cure majors were based upon the obvious method of digging out 
the colony. This proved to be the worst possible way to get them. 
Under ordinary conditions only two or three majors stay in the 
passages near the nest entrance. Since the major of militicida is 
extraordinarily clumsy, it is seldom able to extricate itself if covered 
with soil. Hence, it is extremely likely to be missed when the nest 
is dug out, for the major will often remain perfectly quiet if only 
a thin layer of soil covers it. To be sure that the majors have not 
been missed, the soil must be sifted as the nest is excavated. With 
this in mind it is easy to understand why half the nests which Cole 
excavated in the summer of 1952 (3) appeared to contain no majors. 
During the first weeks of this study we faced a similar situation. 
Three of the eight nests excavated had yielded no majors. The re- 
maining five had yielded a total of only fourteen majors, of which 
the greatest number taken from a single nest was five. Our results 
were, therefore, inconclusive for in no case had numerous majors 
been found in any nest. 
Then the junior author hit upon a method of using bait to bring 
the majors out of the nests. The best bait was found to be various 
sorts of bread or scrambled eggs. Meat seemed decidedly less at- 
tractive. 1 he bait was cut into pieces too large for the minors to 
move and these were placed close to the nest entrance. Phis baiting 
seldom failed to produce majors in quantity if continued long enough. 
