Colorado Parks and Wildlife lists three tree squirrels in the state. The fox squirrel, about 20 inches long and deep rust to gray, is the one living in neighborhood trees. Pine squirrels keep to high timber forests and Abert's squirrels to ponderosa pine, so homes in the mountains around Estes Park can see different squirrels than homes on the plains.
Squirrels have powerful teeth that are constantly growing, and aluminum, vinyl and wood are no match for them. Mature street trees and power lines give them a route to the roof, and once a squirrel finds a weak spot in a soffit or vent it can make the opening larger with its teeth and claws.
Colorado rules also shape the plan. Colorado Parks and Wildlife allows a tree squirrel to be relocated only within 10 miles of where it was caught, with advance notice to CPW and the release landowner's permission. Our squirrel work is built around exclusion instead: once the way back inside is closed, the mother moves her young to another nest site.
For your home, that means we treat an active nest as a possible nursery, check for young before closing any opening and pair removal with the screening and cleanup the attic needs.