▁to ▁be ▁executed ▁in ▁a ▁supp ression ▁hierarchy . ▁This ▁means ▁that ▁gro oming ▁behav iors ▁that ▁occur ▁at ▁the ▁beginning ▁of ▁the ▁sequence ▁prevent ▁those ▁that ▁come ▁later ▁in ▁the ▁sequence ▁from ▁occurr ing ▁simultaneously , ▁as ▁the ▁gro oming ▁sequence ▁consists ▁of ▁mut ually ▁exclusive ▁behav iors . ▁This ▁hierarchy ▁does ▁not ▁prevent ▁D ros oph ila ▁from ▁returning ▁to ▁gro oming ▁behav iors ▁that ▁have ▁already ▁been ▁accessed ▁in ▁the ▁gro oming ▁sequence . ▁The ▁order ▁of ▁gro oming ▁behav iors ▁in ▁the ▁supp ression ▁hierarchy ▁is ▁thought ▁to ▁be ▁related ▁to ▁the ▁priority ▁of ▁clean ing ▁a ▁specific ▁body ▁part . ▁For ▁example , ▁the ▁eyes ▁and ▁anten na e ▁are ▁likely ▁executed ▁early ▁on ▁in ▁the ▁gro oming ▁sequence ▁to ▁prevent ▁de br is ▁from ▁inter fer ing ▁with ▁the ▁function ▁of ▁D . ▁mel an og aster ’ s ▁sens ory ▁org ans . ▁ ▁Walk ing ▁▁ ▁Like ▁many ▁other ▁hex ap od ▁insect s , ▁D ros oph ila ▁typically ▁walk ▁using ▁a ▁tri pod ▁g ait . ▁This ▁means ▁that ▁three ▁of ▁the ▁legs ▁swing ▁together ▁while ▁the ▁other ▁three ▁remain ▁station ary , ▁or ▁in ▁st ance . ▁Vari ability ▁around ▁the ▁tri pod ▁configuration ▁appears ▁to ▁be ▁continuous , ▁meaning ▁that ▁f lies ▁do ▁not ▁exhib it ▁distinct ▁trans itions ▁between ▁different ▁ga its . ▁At ▁fast ▁walking ▁spe eds ▁( 1 5 – 3 0   mm / s ), ▁the ▁walking ▁configuration ▁is ▁mostly ▁tri pod ▁( 3 ▁legs ▁in