The industry has also researched discouraging squirrels by spraying utility poles with fox urine and painting equipment red, though both of these tactics have failed; it’s not even clear whether squirrels can see the color red. Some utilities have installed the kind of plastic owl used to keep pigeons off building facades. However, an industry study notes, “one utility reported that the fake owl was attacked by a hawk which in turn caused a substation outage.”

AT some point this summer — I think it was around July 31, when just under 13,000 customers got hit by a P.O.C.B.S. in Hendersonville, Tenn. — I found myself trying to imagine power outages caused by squirrels from the squirrels’ point of view. So I called John L. Koprowski, a squirrel biologist at the University of Arizona, Tucson.

There have been very few squirrel specialists throughout history. The most accomplished was Vagn Flyger, a University of Maryland biologist who trapped squirrels with a mixture of peanut butter and Valium and then affixed them with radio transmitters; his major contribution to squirrel science was mapping the so-called Great Squirrel Migration of 1968 across the Eastern Seaboard. (Mr. Flyger also liked to eat squirrels.) Mr. Koprowski started studying squirrels as a biology student in Ohio because he needed to study some sort of wild animal and he didn’t own a car.

Essentially, Mr. Koprowski explained, power outages caused by squirrels are the product of a cascade of coincidences — of various forces, including basic squirrel behavior, colliding.

Squirrels chew through electrical wiring because the animals are constantly teething. An adult squirrel’s incisors never stop growing — they can grow as much as 10 inches per year — and the animals must chew constantly to keep them worn down. Squirrels gnaw or burrow their way into transformers for the same reason they enter rotting cavities of aging trees: hollow spaces offer them den sites and safety from predators. Squirrels break into equipment at substations because the seeds and insects they eat get sucked into that machinery by cooling fans, or are pooled inside by the wind. Mr. Koprowski described the flat tops of transformers as perfect spots for squirrel “basking behavior,” when squirrels sprawl out in the sun to warm up, or in the shade to cool down, and also ideal “runways” from which squirrels can start their flying leaps into the canopy.

“Squirrels value many of the same things that humans value,” Mr. Koprowski explained. It’s why they’re among America’s most successful synanthropes, what biologists call species that thrive alongside humans, in the landscapes we dominate. The beautiful, shade-producing, property-value-raising trees that we’ve filled our neighborhoods with, like oaks, walnuts, maples and elms, also produce the seeds, nuts and acorns at the core of the squirrel diet. Thirty-five percent of America’s urban areas are now covered with trees, while sprawl and exurban development have pushed homes further into formerly natural areas. Squirrel habitat and our habitat are increasingly converging. And we are only now reaching what may be peak P.O.C.B.S. season. In late August and September, squirrels are both abundant and most active: skittering around, stockpiling food, hustling to get stuff done before winter — more prone to crossing paths with the path of our electricity.

“People are living in areas with higher squirrel densities now,” Mr. Koprowski said. It’s as simple as that. We’re getting in their way, too. It’s easy to forget that the party most inconvenienced by a power outage caused by a squirrel is the squirrel that caused it.