To the left in the photo taken by one of our technicians you can see a joist inset in a foundation wall, with a
sharp grease line that goes under it. That is a classic rodent
rub mark, from years of rodents running along the sill, encountering the joist, and running quickly down the wall, under the joist and back up. Rodents can easily run sideways on any porous surface, as illustrated by this rub mark.
-Lauren Greenhow, General Manager, GreenHow, Inc.
http://www.greenhow.com/. Effective Organic & Low Impact Solutions, Lawn Care, Pest Control & Termite Control in Newton and Metro Boston.