Key Habits for Achieving Control With Roof Rats

With roof rat pressure on the rise along the I-5 corridor from San Diego to Seattle, commercial property owners and managers are being pressed hard to find solutions to controlling this cryptic pest.

Prone to gravitate to the ‘shadows’ in structures such as rafters, corners, crevices and along roof lines, roof rats are cautious and secretive.

Leading rodentologist Dr. Bobby Corrigan recently shared his insights into managing roof rats on a Sprague Pest Solutions Spotlight webinar. He emphasized the need for facility managers and their pest control service providers to not only understand roof rat biology and behavior, but construction basics as well.

“You need to identify the lines, ‘shadow areas’ and nooks and crannies where they are active,” says Corrigan. “You must be the hunter when it comes to finding them.”

Corrigan says roof rats travel and nest out of sight and true to their origins in Southeast Asia where they traveled on ‘treetops.’ The equivalent in a structure would include electrical wires, cables, pipes, ledges, and exposed beams. An extra pad on the roof rat’s back foot – something the Norway rat doesn’t have – allows it to easily navigate both vertical and horizontal structural elements.

Since roof rats travel and nest in hard to reach, out of sight areas, they require a different management approach than other rodents. An approach that can be a more time consuming, costly and challenging.

“You must take the control equipment to the roof rat versus them coming to it,” says Corrigan. “Time must be invested to make the proper identification and perform a comprehensive inspection if you want to arrive at an effective solution.”

Corrigan recalled performing an inspection in a food distribution facility where he used a pair of binoculars to the read the top sill plate of the hollow concrete block walls for evidence of roof rat activity.

Key Habits for Controlling Roof Rats

  1. Roof rats are active and travel in areas of dense cover or cloaked in darkness.
  2. Analyze structures for shadows, tight elements and lines when designing a control program.
  3. Roof rats feed more like mice than typical rats. They are hard wired to natural foods such as tomatoes, cucumbers, nuts and seeds
  4. Roof rats are often found traveling along aerial lines in a structure. If you follow the lines, you’ll find the roof rats.
  5. Landscaping (shrubs, bushes, trees, etc.) in fence corners or covering fence supports are ideal travel lines for roof rats.
  6. Adult roof rats are more secretive than Norway rats.
  7. Roof rats display inconsistent foraging behavior.
  8. Roof rats have will travel from 100 to 300 ft. from their home nest and that could mean a neighboring property is the source of the infestation.

For more information on how Sprague Pest Solutions can design an effective roof rat management program for your facility, call 855.805.0755.

Register for the next Sprague Spotlight Webinar – Innovations in Pest Management: Technological Advancements to Improve Your Pest Management and Food Safety Programs on Wednesday, August 19 at 10 a.m. PST. Register at

Commercial Properties, Education & Schools, Food Retail & Grocery, Healthcare, Rodents: Rats & Mice