Dispersal of the crawfish Fazonella clypeata in a linear environment does not show a density—dependent relationship in populations of 1, 5, 10, 20, and 30 animals. Crawfish without chelae moved approximately the same distance per time period as intact animals. Animals with antennae or eyestalks absent moved less than intact animals. The control of locomotion by a hormone originating in the eyestalk possibly explains why eyestalkless animals had very little movement. The means for the dispersal of intact male and female groups were not significantly different from each other. The innate tendency toward dispersal may be found in some crawfish species demonstrating intra—specific aggressive behavior.