In fact, those incisors never stop growing. No only can rodents gnaw, they must gnaw everyday to keep their teeth from growing to too long. Constant gnawing also keeps the teeth razor sharp.
Pack rats are notorious for their gnawing ability. Below are some examples:
Trapped rat chewed through side door to get out of a garage.
Hole chewed through roof deck. Was hidden under tile.
Roof deck under flashing around a vent.
Bench seat cushions. Stuffing makes great nest material.
Small gap at beam enlarged into a hole big enough for the rat to use.
2x4 in the way? No problem!
Romex 110V wiring in an attic
The gray metal is lead flashing chewed through.
Foam sealant is no match at all.
More lead flashing chewed for about 12 inches.
Underside of a heavy duty drain cover chewed all the way through.
Pack Rats often use drain pipes to move around and hide in.