We have lots of black widow spiders here - some are pretty good size too. We leave them alone and they avoid us! A big problem here are hornet and wasp nests in attics - we always have a can of hornet and wasp blaster in the van.
Working in an old apartment building that had a 60 amp fused disconnect feeding a sub-panel. Someone had punched open the knockout from the back above the line terminals, and there was a hole in the wall directly behind it. Laying between the two terminals was the skeleton of a mouse which was electrocuted and had been there for many years.
