1966] 
Creighton — Pheidole 
3 
in the walls of the excavation. But to follow these passages to their 
ends was quite another matter. Although some of them were traced 
to a distance of two feet from the main shaft, no brood chamber 
or seed chamber was found. Nevertheless, it is possible to state that 
the nest of ridicula is diffuse with the seed and brood chambers widely 
separated. 
The foraging responses of ridicula are flexible and this makes them 
difficult to describe. Much of the foraging occurs at night but it is 
misleading to characterize ridicula as a nocturnal forager. If the 
nest area is shaded, or if the day is overcast, foraging may occur over 
a twenty-four hour period. Even when the nest is not shaded foraging 
ordinarily continues until mid-morning. Foraging may be diffuse or 
the foragers may form columns. Most of the seeds brought in are 
picked up from surface litter and in this type of foraging columns 
rarely form. But when a concentrated food source is at hand, the 
foragers will converge on it and a column may result. The foragers 
seldom get far from the nest. In each of the seven colonies most of 
the foraging was done within ten feet of the nest entrance. The 
majors take no part in the foraging although they will leave the 
nest with the minors. When they do so they restrict their patrol to 
the area around the nest entrance and it is exceptional to find them 
more than a foot from it. During vigorous foraging there may be 
several majors outside the nest and their activities effectively clear 
the area of other ants. 
There is little about the appearance of the major of ridicula to 
suggest its lethal behavior. From a structural standpoint Wheeler’s 
choice of name is apt enough, for it would be hard to imagine a more 
top-heavy ant. But there is nothing ridiculous about the major in 
action. When it is on guard, either within the nest entrance or out- 
side it, it attacks other ants with such efficiency that the victim 
usually has no chance to defend itself. The basic features of this 
attack are the same as those described for the major of militicida 
in 1959 (2). As the ridicula major approaches its victim the man- 
dibles are opened to their widest extent. This is followed by a rapid 
lunge towards the victim during which the mandibles are snapped 
shut. Unlike the militicida major the major of ridicula does not hold 
the antennae close to the head during attack. They are usually held 
with the scapes at right angles to the long axis of the head and with 
the funiculi flanking the open mandibles (See Fig. 1). Because of 
the lateral expansion of the genae the mandibles can be opened to 
an astonishing extent, with the result that the major of ridicula 
seldom has difficulty getting the head or the thorax of its victim 
