We live on 5 acres in central Texas. Our soil is sandy which makes for great riding but is also great for fleas. We can not get rid of the fleas. We have sprayed, bombed, dusted and even used DE in the barn, yard and the house but nothing is working. We have used Frontline, Advantage and even Comfortis on the dogs but they still have fleas. We have 4 dogs and 3 barn cats so we are spending a fortune each month to get rid of these nasty creatures. I feel like I am slowing killing my animals not the fleas. Any ideas?