Some of the good old boys up country call them "Flatrats", ie, a rat with a flat tail. They can be a real headache for someone who makes their living from forestry, whether it's tree farming or maple slyrup or seedlings. Anything that sneaks into your woodlot at night and kills sixty prime hardwood trees in a week is deemed a rat by some.

Much worse is a "Treerat" or "Pickrat". A porcupine can cause severe damage because they often go undetected until major damage is done. Unlike beavers, they can be anywhere, anytime. The worst of these is one who has lost the ability to climb. It will eat the bark as high as it can, around the entire butt, and move to the next tree. And, contrary to popular belief, they will eat smooth-bark softwood.