When I was a kid my town had three blackouts caused by substation failures.  Once by mylar party balloon, and twice by squirrel. Turns out having a bushy tail can be a liability.<p>Later I was reminded of this when I was reading a biography of Tesla, who was doing the calculations for the arcing distance on his equipment and was building the largest coils that could safely be placed into his workshop(s).  One day he accidentally turned on the equipment while he was on the wrong end of the room and he had to army crawl across the floor to get to the shutoff switch without turning into one of those squirrels.<p>[Edit] The point:  Maybe we&#x27;re designing the safety margins on these systems a little too tightly.  Maybe a Squirrel radius should be added to these things.