Actually, when I had that job, I always carried an old single action .22 revolver loaded with birdshot. The occasional ugly spider wasn't as bad of a deal as the occasional rattlesnake. This was the chlorinator building / control room of the local water system. I was the operator. Building was 8 by 14 concrete block, with a 7 foot ceiling of poured concrete. Anything other than birdshot would still be ricochetting around in there, lol.
