Abstract: Understanding the factors that influence habitat selection is important in explaining the behavior of a species. Movement within a habitat depends on how and why an individual in a species chooses its habitat, which in turn may depend on density. Fretwell and Lucas's Ideal Free Distribution has been shown to occur in several study species, and ecologists are interested in determining whether or not this distribution does indeed describe nature. Although the effects of density on habitat selection within a population have been studied within some species, the distribution among brackets in population of forked fungus beetles ( Bolitotherus cornutus ) has not yet been explained. The movement of these beetles and their ability to select their habitat can easily be tracked. This study explored how density of colonies affects the distribution of forked fungus beetles among brackets of different quality and size. The densities of colonies in an area near Mountain Lake Biological Station in Giles County , Virginia , were manipulated, and mark-recapture methods were used from May 10 to July 20, 2006 , to determine whether or not the Ideal Free Distribution describes this system. Furthermore, the sex, condition, and horn length of the beetles were examined to determine if a relationship exists between these phenotypic traits and habitat selection. Ideal Free Distribution was found to occur in this population of B. cornutus , with the beetles selecting their most suitable habitats based on quality. Habitat selection by bracket size was found not to be density-dependent. Males of longer horn length were found to inhabit brackets of better quality in low density colonies possibly as a result of higher success in battles over mates and territory. Furthermore, females were found more on smaller brackets than males possibly due to the lack of intrasexual competition.