Well, I don't want the little beasties to suffer, but my other options were not working. I would happily try something that ensures instant death, but the traps and water buckets and stern warnings were just not working. And of course, the worthless catch and release cat wasn't even remotely scaring them off. The peace treaty that I signed very clearly states that I will not tromp around in their kingdom (aka the pasture) as long as they don't tromp around in mine (any area that I bother to mow). I have kept to my side of the boundary line. The rats are the ones in violation. Shock and Awe was the only plan that was going to work. Sometimes you have to go in strong.
(By the way, this is the same treaty that I hold with the snakes. THey can do their snakey thing in the tall grass and I will hang out in the short grass. There are clear lines of demarcation.)