My husband and I are having a disagreement about our new run. The fencers made an apron that is 15" out from the run, but did NOT dig a trench for it 1.5 feet down. We had a gopher (I think) tunnel in from several feet outside the run right into the run. I say our run is vulnerable. Another animal could do the same as the gopher, or use the gopher hole to come into the run. My husband says 'no way.' Who's right? Our first run has both an apron and is dug into a trench 1 foot down. We haven't had any problems with that in the time we've had it (over a year). We have had a "visitor" leaving scat recently. It looks like possum scat. Can they dig under? We have used hardware cloth throughout.