"Flooding" doesn't kill gophers

This demonstration showed that surface water couldn't enter cavities in the soil except through an opening at the ground surface or if the water table rises. Gophers can block their tunnels with soil and create such pockets during heavy rains or flooding.
 
A pocket gopher was placed in a wire mesh tube (with food), buried several inches underground, and then the area was flooded. (The glass tube in the center of the photo provided air.) A hose was used to keep the area under water for several days.
 
To determine whether the gopher was still alive, every day we inserted a string down the glass tube into the wire tunnel. Within a few minutes, the gopher would grab the string and pull — moving the small stick to the top of the glass tube.