Mutant males and females show a significant reduction in both nighttime and daytime daily sleep compared to controls. Waking activity (activity/minutes awake) is similar in the mutant flies and in controls. There is a significant reduction in sleep bout duration during the night in the mutant flies compared to controls, indicating a defect in sleep maintenance. Sleep bout number in mutant flies is higher than in controls. Mutant flies show significantly increased sleep rebound after mechanical sleep deprivation compared to control flies. The mutant flies have reduced arousal thresholds from sleep compared to controls.