go to Lowes and buy 2 or 3 "Rescue" fly traps. They catch them by the thousands. Best thing for the $.

Rescue fly traps work well, but I also supplement by spray "TALSTAR" around & in the kennels. You get it from Southern States, mix 1 ounce per gallon.
When you spray the kennels, take the hounds out first, spray kennel, let it dry, and then put hounds back in kennel. That is according to their directions. Better to be safe than sorry, but the product works extremely well. I normally put down a second application within two weeks, and no more fly problems.
Bayer insect spray will work also!
Hope this helps.

ALLAN BISHOP
(JABBER JAW)

I can speak to the efficacy of the rescue traps. I'd use them in conjunction with the Bayer insect spray, but take the dogs out first like the man said then put them back when the spray dries.