From a rat’s perspective, any place that he calls home must have a back door as an escape route. All burrowing animals, like the Norway rat, have a great fear of being trapped in a tunnel or confined space when a predator follows them, or tracks them into, an opening.
Rats who enter your crawl space through a torn vent screen will try to find, or make, a back-door escape route. They will start by exploring and testing the strength of all the other screens.
Sometimes they will burrow under your foundation from the inside. Look for smooth round holes near the foundation with no mounding, or any dirt around them.
Sometimes they will find a gap around the sheet metal duct work in your crawl space that comes from your furnace. They are attracted to the warmth in the winter and use these defects to enter the garage or living area. If rats get into the garage they will always attack the garage door seals and try to chew through the corners to make an exit. In some cases, they will use existing plumbing and electrical conduit holes around appliances to enter a kitchen.
Roof rats will often enter via an old squirrel hole in the eaves and then proceed to chew more holes in the roof area, as well as exploring the rest of the house, including the basement or crawl space. Our parent company, Nature First Pest Control, has caught hundreds of roof rats in crawl spaces.
If you suspect you have a rodent issue, or ‘Smell a Rat’
Call Crawl Space Portland 503-789-1227