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Psyche 
[Vol. 88 
nest overdispersion is frequently confused with, or taken as evidence 
for, territoriality although crucial behavioral patterns are not 
considered. However, sufficient information is available in the 
literature to suggest some of the behavioral and ecological factors 
important in the regulation of nest distribution. 
With the above cautions in mind, we here present a simple model 
of predicted spatial distributions of colonies under different ecologi- 
cal conditions. We then survey the literature to examine the fit of 
available data to our predictions. Finally we discuss the general 
problem of the form of interactions between colonies and some of 
the implications of this for both field and theoretical considerations. 
Theoretical Aspects of Nest Distribution Patterns. 
We would first like to develop a set of biologically realistic 
predicted spatial distributions of colonies. We begin by positing 
some simple assumptions about a hypothetical ant population: 
1. Nest sites are unlimited. 
2. The habitat is homogenous and inhabited by a single species. 
3. Each colony forages symmetrically around the nest to some 
distance r, which forms the radius of a circle. Within this circle, no 
other colonies can forage or become established. 
Simberloff (1979) derives the maximum foraging distance, r, as 
sly 
4 \/3 \/p 
where p is the density of nests. In this case, nests are hexagonally 
packed and the array of nests is overdispersed (more regularly 
spaced than expected if random; Figure 1, case 1). Nests are spaced 
2 r apart and have 6 equidistant nearest neighbors. 
Under different ecological conditions, the expected spatial dis- 
tribution of nests will change. In low density populations, nest 
distribution should reflect the best foraging or nest sites; nests may 
be dispersed in any way and should tend towards a random 
distribution (Figure 1, case 2). Internest distance should on the 
average be at least twice r and usually more; its variance should be 
high. If nest sites are not uniformly available, then nest spacing will 
