Homozygous adult escapers are occasionally seen. These escapers do not show abnormalities in the thorax or in wing hair polarity. The adult escapers are grossly uncoordinated and on eclosion they immediately fall into the food and die. If the flies are retrieved before they get stuck in the food, they are unable to fly and show a severely delayed righting reflex and although they appear to walk normally, they have impaired climbing behaviour.