When critters cut your power When critters cut your power

When critters cut your power

Animals cause thousands of power outages. What are energy companies doing to prevent them?


They’re cute, funny and entertaining, especially when they’re climbing trees and darting back and forth across your yard.

And they can be incredibly destructive.


When it comes to power outages, squirrels are Public Enemy No. 1, but some of their other critter relatives are not far behind.

“Storms and downed trees cause most power outages,” said Misti Sporer, Lead Environmental Scientist for Duke Energy, “but animals dish out their share of damage.”

Just how many outages do critters actually cause?

Through July 2016, Duke Energy has attributed about 1,000 outages to squirrels in its service areas. At least 1,000 more outages were caused by a variety of other animals, such as vultures, snakes and raccoons. According to the United States Energy Information Administration, about 13 million people nationwide were affected by critter-caused outages last year. And it’s relatively easy for technicians to discern when a critter caused an outage – most likely, his charred body is still there.

How do the outages actually occur?


Squirrels often get into trouble because of their natural curiosity and like infants, they are constantly teething with a tendency to gnaw on things – including electric lines. They meet their maker when they come in contact with both the energized wire and either a ground or another energized component. They “complete the circuit,” becoming a conduit for electricity to flow through. The action is not always fatal; sometimes, the animal just gets a scary shock.

Is it just squirrels that cause issues?


Squirrels are particularly pesky, followed by birds, raccoons, rats, skunks, snakes and even an occasional fox. Of Duke Energy’s outages in 2016, most were squirrel related. Other animal-caused outages may be difficult to detect because no carcass is found or the remains are unrecognizable. Animal-caused outages can be masked by a catastrophic failure or a bird collision (sometimes the injured bird flew off).

Many of these creatures are attracted to the humming warmth of electrical equipment, while snakes slither into substations looking for food, often bird’s nests.

What are some of the most recent unusual animal-related outages?

  • In Liberty, Texas, thousands of tent caterpillars hatching from eggs in trees covered transformers, resulting in numerous power outages.
  • Two days after Thanksgiving  2015, a turkey made its way into a North Platte, Neb., substation and caused a large-scale outage. More than 6,000 customers were left in the dark for about an hour.
  • Critters01A
    At Duke Energy, two of the oddest animal-related outages involved a cow and an osprey. Cows like to use guy wires as back scratchers. In Mooresville, N.C., a cow rubbing against a guy wire broke a primary line. When Duke workers arrived, they found the cow lying on its back, with all four legs up in the air. The cow didn’t fare well in the end. Near Kannapolis, N.C., an osprey, a large raptor with a 5- to 6-foot wingspan, built a nest on a pole. While the bird was landing, its wings came down between two energized wires, causing an outage.

What are utilities doing to reduce these issues?

Duke Energy studies animal habits and outages and looks at reduction strategies. The company erects special fencing or “critter guards” to keep squirrels and other creatures out of substations. The company also places equipment so it’s difficult for animals to provide a path for the electricity to flow.

Entergy Texas puts plastic spinners on power lines at substations to keep squirrels off and Cantega Technologies in Canada markets covers for substation equipment.

Follow cybersquirrel attacks

CyberSquirrel1 website tracks power outages caused by squirrels worldwide.

Duke Energy’s Natural Resources group manages an avian protection program for the company. This plan outlines ways to keep birds safe on power lines. Duke Energy has built platforms or provided nesting boxes for birds, as an alternative to using company equipment.

Using these methods, Duke has been able to cut animal disruptions in half over the past decade.

Still, challenges remain. “First and foremost, we want to keep the lights on,” said Sporer, “but we do take steps to prevent harm to animals; that’s something we continuously improve upon.”

illumination Staff Writer Dennis Lockard contributed to this article.


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