Spatial distribution patterns were examined for four different experimental groups of flesh flies (single females, single males, groups of four females, and groups of four males) placed within artificial enclosures, rectangular and circular, under controlled laboratory conditions. In the rectangular enclosures, food was located on one end and water on the other. In the circular enclosures, water was located in the center and the food was located either in the center or along the peripheral edge. Results for experiments using the rectangular enclosures include (1) no end effects for any of the experimental groups, (2) a significant food effect for all groups, as flies preferentially situated themselves in the section of the enclosure nearest the food, and (3) a significantly higher tolerance among females than males for individuals occupying the same spatial location. Major findings for experiments using the circular enclosures include (1) a significant edge effect for all experimental groups, (2) significant enhancement of the edge effect by placing the food along the enclosure edge for groups of four flies but not for single flies, (3) a near-random distribution for females in groups of four but a more uniform distribution, suggesting maintenance of inter-individual spacing, for males in groups of four, and (4) relaxation in males from a uniform spatial distribution exhibited under light conditions to a near-random distribution under dark conditions. These results suggest fundamental differences in inherent spacing behavior between male and female flesh flies.