Yeah that makes sense. I have a pinpointer. Not a good one though. Going to order a pistol probe this week. But anyway. The thing that is weird is that when I dig and come smashing threw these gophers roof. The signals just vanish. No more signal. However. I might just start checking them out when I get the pistol probe. If they hoard shiny things then its worth a look around.
Also, I dunno if you have noticed. But, seems that I find grubs 95% of the time when I dig up a hole that has a coin in it. So, I consider these larva a good sign. They must like the minerals or something.