Mutant flies show a reduction in sleep duration compared to controls. Sleep is reduced during both light and dark periods, but the sleep levels of the mutant flies drop in anticipation of light-dark and dark-light conditions, suggesting that the circadian clock is intact. The mutant flies show a reduction in sleep bout length accompanied by an increase in sleep bout number and show an increased latency to sleep after lights-off. The mutant flies show a modest reduction in activity during wakefulness. The mutant flies show reduced sleep homeostasis, lacking a detectable sleep rebound after 12 or 24 hours of sleep deprivation. The mutant flies are more easily woken by a rotational stimulus compared to wild type controls.

A proportion of mutant flies lack either an α- or β-lobe in the mushroom body.