Hint – we’re losing.
I remember having gopher & mole problems when I was a little kid in the KC suburbs. My dad didn’t want to use poison, not because of any sentimental reasons for the rodents, but because there were eight kids running around the yard and kids are stupid. Instead, he would hook up a couple of garden hoses and ram them about 20 feet down the holes, then turn on the water for an hour or so until the entire yard had water popping up from all of the holes.
Despite the questions I have about the efficacy of that method, with the price of water in SoCal these days, that sounds like a perfectly good waste of $25,000 worth of water, so let’s give that a hard, “NO!” On the other hand…
CO2 is heavier than air and will sink. This is why folks have died in certain industrial environments when the tank or tunnel or bowl they’re working in gets flooded with carbon dioxide.
I have a couple of expired CO2 fire extinguishers. I can also get dry ice, which is solid CO2, which will turn into gaseous (and heavier than air) CO2 as it sublimates. So what would happen if I shot off these CO2 fire extinguishers into a few holes, following them up with big chunks of dry ice shoved down deep into every hole I can find, then sealing them off with dirt. Wouldn’t that CO2 stay down in the holes and tunnels, more or less, suffocating the little varmints?
Circumstantial evidence would make me think that it wouldn’t work or would have some other side effect, since I don’t know of any professional exterminators who use that method. It seems so easy, and relatively cheap, so if it would work everyone would be doing it, right? Conversely, since no one does it, it must not work? Right?
Or else I just revolutionized the critter elimination industry. Either way.