What with the combination of the weather here 'bouts this spring, living on a horse ranch, keeping ducks and chickens the fly problem has been particularly bad this year. Than I remembered a suggestion that I'd read here on BYC. It seemed worth a try so I went to WalMart and bought a couple of packages of Little Tree X-tra Strength Vanillaroma air fresheners. ( http://www.little-trees.com/us/products_detail.php?section=products&id=9 ) Six for about $4.50. I hung them full strength around the house near windows and doors in the air flow. About an hour and a half later the flies were all but gone, and they haven't come back. While the scent is kinda overpowering at first it's not objectionable, and I quickly got used to it.
Next, the penultimate test; the duckling grow-out pen is on our screened-in back porch and flies were atrocious. We'd even tried those smelly bag fly traps to no avail. I hung six Little Trees down there and waited. It took about 3 days, and the flies are all but gone.
Usually works, but nasty smelling:

Works, smaller and smells nice:

The winner for indoor fly control is (drum roll) Little Trees by a landslide!
Next, the penultimate test; the duckling grow-out pen is on our screened-in back porch and flies were atrocious. We'd even tried those smelly bag fly traps to no avail. I hung six Little Trees down there and waited. It took about 3 days, and the flies are all but gone.
Usually works, but nasty smelling:
Works, smaller and smells nice:
The winner for indoor fly control is (drum roll) Little Trees by a landslide!