▁the ▁ph er om one . ▁An ▁example ▁is ▁c VA , ▁an ▁anti - aph ro dis iac ▁ph er om one ▁used ▁by ▁males ▁to ▁mark ▁females ▁after ▁cop ulation ▁and ▁to ▁d eter ▁other ▁males ▁from ▁m ating . ▁This ▁male - specific ▁ph er om one ▁causes ▁an ▁increase ▁in ▁male - male ▁ag gression ▁when ▁detected ▁by ▁another ▁male ' s ▁g ust atory ▁system . ▁However , ▁upon ▁inserting ▁a ▁mut ation ▁that ▁makes ▁the ▁f lies ▁ir respons ive ▁to ▁c VA , ▁no ▁ag gress ive ▁behav iors ▁were ▁seen . ▁This ▁shows ▁how ▁there ▁are ▁multiple ▁modal ities ▁for ▁prom oting ▁ag gression ▁in ▁f lies . ▁ ▁Compet ition ▁for ▁food ▁ ▁Specifically , ▁when ▁compet ing ▁for ▁food , ▁ag gression ▁occurs ▁based ▁on ▁amount ▁of ▁food ▁available ▁and ▁is ▁independent ▁of ▁any ▁social ▁interactions ▁between ▁males . ▁Specifically , ▁suc rose ▁was ▁found ▁to ▁stim ulate ▁g ust atory ▁re ceptor ▁neur ons , ▁which ▁was ▁necessary ▁to ▁stim ulate ▁ag gression . ▁However , ▁once ▁the ▁amount ▁of ▁food ▁becomes ▁greater ▁than ▁a ▁certain ▁amount , ▁the ▁competition ▁between ▁males ▁low ers . ▁This ▁is ▁possibly ▁due ▁to ▁an ▁over - ab und ance ▁of ▁food ▁resources . ▁On ▁a ▁larger ▁scale , ▁food ▁was ▁found ▁to ▁determine ▁the ▁boundaries ▁of ▁a ▁territory ▁since ▁f lies ▁were ▁observed ▁to ▁be ▁more ▁ag gress ive ▁at ▁the ▁food ' s ▁physical ▁per imeter . ▁ ▁Effect ▁of ▁sleep ▁dep riv ation