Porcupines are becoming a prickly pest for Telluride-area residents.

Residents say the rodents are chomping on the bark of spruce trees, yard trees, and have killed 50-foot-high native trees. The damage is estimated at more than $100,000 in the Mountain Village above Telluride.

Porcupines also favor salty and sweaty items, so plywood treated with a sodium-based substance has become attractive to them. They've also munched on shoes, vehicle tires, and tool handles.

Mountain Village resident Vicki Irwin says she's never seen the porcupines be so aggressive.

Some possible reasons cited for the porcupine's behavior are a harsh winter last year that ramped-up their appetites and the rodents can roam freely because many of the town's 4,100 resident's live elsewhere most of the year.