I have a roof rat problem my way in Northern California. The more traps I put in the the more of those bastards I catch. I actually found a way to get rid of them in my attic...I replaced the bathtub. You are now saying WTF? The plumber that originally put in the tub cut a huge hole for the tub drain and never patched it. The rats just climbed up the vent line and snuggled into my walls and attic. For our Canadian friends, we don't have basements in Cali, and we have crawl spaces underneath our bottom floors which critters can find many access points that you are not aware of.
