How to get rid of all the flies?

Flies are attracted to- believe or not- poo! so when you clean out the cage make sure you give the potty corner an extra good scrubbing! Maybe you could research air fresheners?!?! Make sure if you buy an air freshener it won't do anything to your hamsters health! If you find a suitable hang it somewhere near the cage not in it! hopefully that will take away the smell that attracts flies!