There have to be openings, otherwise how do the little guys get in/out? typically the entrance to a gopher tunnel looks like a mound of dirt, sometimes there is no visible opening due to settling of the soil.i was at the lake yesterday. i could see where they were tunneling under the sand/soil. there were NO openings ANYWHERE. just bulging earth where they had tunneled. it looked as if the sand/soil was cracked enough on the surface to allow some air in, but they have to be pretty much surround by loose stuff. i tried to dig down a little to find the tunnel and it all just caved in.