I don't know if this will work for you, but we were having lots of trouble with moles in the flower beds, big tunnels with lots of soil excavated.
We tried baits, traps that didn't catch anything, those guys are fast!!! Flooding the tunnel, and nothing worked.
Then someone told me about this recipe.
1 small bottle of cheap perfume, the smellier and stronger the better. We got some from the dollar store.
1 cup of rubbing alcohol.
Put this in a large bucket and fill with water, then pour the whole thing down the tunnel.
I don't know if it was a coincidence, but they went away and haven't come back. I guess it just smells too good for them.
You could try this, not much to loose and a lot to gain. Please let me know if it works for you.
Josephine.
