Walter, a chemist friend of mine plagued by gophers, tried repellants, housepets, and loud, "thumper" ground noises---all ineffective. His lawn was a mess of lumps and bare spots. He finally brought a bar of sodium home from his lab. He thrust the sodium down the biggest gopher hole, stuck in the garden hose, and flooded the burrow. As planned, the sodium exploded. So did the entire front yard.
It being a lovely May Sunday, all his neighbors were out working on their landscapes. A sudden silence fell over the block as everyone stared at the crater that had been Walter's lawn.
Eventual results: It took Walter over a year to get grass growing again. In the meantime, the gophers moved to this back yard, where they ate all Walter's bulbs and perennials.