Scientific literature has shown that crayfish are aggressive creatures and that aggression manifests itself in various situations where resources such as space or food are limited. The experiment was designed to test the possibility that a decrease in available space for the crayfish Orconectes virilis would increase the amount of agonistic behavior between the observed crayfish. By studying crayfish from Lake Itasca, the goal was to determine if a decrease in space was a situation that caused crayfish to be more aggressive to each other. Using a fish tank and a movable wall, the amount of space given to the two crayfish is decreased by ten centimeters twice, thus giving three separate space increments of behavior to observe. The results showed a significant difference in the behavior frequency between the first and third space increments.