What can I do to get rid of flies under rabbit cages?

the droppings and urine fall thru the cages on the ground and even though you shovel it up the flies are still bad.

Only thing i can think of is try a bag of that diazinon crystals , you can get it at Wal-Mart , etc. You spread some out on the ground and get it wet (slightly). It's worth a try....

Plant mint or hang bags of water. Mint is a natural way to help keep flies away and it will make the area smell better~hanging ziplock bags with water will scare the flies off. The water reflects onto the flies many eyes and makes them think it is some kind of predator.

Various pesticides and sticky fly paper would work to some degree. Cyflurin is the chemical name of a relatively safe insecticide. The key thing to do is to not have the rabbit in close contact with the area you spray. This chemical is basically harmless to mammals if used to correctly but is harmful to fish. It is availiable at walmart, lowe's, and the home despot. Bayer(yep like the aspirin) and Ortho(yep like the birth control) make versions of this and probably many others. Be sure to follow label instructions.

Tame some gecko lizards. The lizards will eat the flies.

clean it every day

When you've done cleaning the cages every day and putting the lizard under them let me know how it works. Who cleans the lizard?

There are products called "Fly Predators" they work amazingly well. I have been using them about 2 years,'Check out www.spaldinglabs.com