They dug all along the fence, so we put a wire fence along the dirt to keep them out. However, they just deep digging! I sprinkled red pepper flakes... didn't work... any ideas/suggestions?

Well it's in their nature as ground hunters.

You can try turning on the hose when you see them digging (only if the weather permits).

Some people say that putting your dogs own feces will deter them from digging in that one spot, some trainers even say to sprikle meat tenderizer on their food, because this will really make the poop repulsive to them. I am not sure how reliable this is, as I've never really had a digger before.

You can try some more distractions in the yard like new toys or treats to have while out there. Also if they are exercised a lot, they will be too tired to dig.

You can try providing them with an acceptable digging area like a sand box. When ever you see them digging by the fence you can put them in the sand box.

Thanks for the input... will walk them more and I have been hosing them and that does work. Thanks again!