Squirrels and birds are the common causes of outages. Metal brackets are flat, and squirrels use them as perches. Metal brackets are strategically replaced with brackets made of fiberglass tubes, reducing the number of outages caused by squirrels. Plastic covers are also added to the tops of transformers, further reducing outages.
Some poles are popular among woodpeckers, which can cause significant damage. Special sheets are wrapped around poles and attached with fiberglass pins.