Field Notes: Rodent Control

General recommendations

• Keep doors closed
• Seal cracks around doors that are seldom used
• Perform thorough maintenance on the facilities, concentrating on cracked concrete foundations, sagging doors, damaged doorway seals, missing or loose siding, damaged or deteriorated caulking around any type of opening.
• Use closed cell black expanding foam (Touch ‘N Foam) in small openings of 1/2” width or less. Use open cell yellow expanding foam (Triple Expanding Foam) in larger openings. Perform the task with care, keeping the foam as neat as possible, avoiding jagged edges that rodents can gnaw on.

Specific recommendations

• Rotate bait active ingredient and presentation type.
• If the previous rodenticide used was a “chunk or block” bait, consider using a soft bait. Not a mandatory practice, but the newer bait offerings gives this opportunity to present an extra element of change to the rodents.
• Check the active ingredient of the current rodenticide. Make sure to change to a completely different active ingredient.
• Mow as much of the perimeter vegetation as possible. Reduce the height to 5 inches or less, and don’t drive through wet areas and create ruts which will hold water or prevent future mowing.
• Physically inspect each bait station. Verify the number of bait stations present and their location. If bait stations have been damaged, lost or are worn out, replace with new stations. Make sure the stations are placed at the correct interval and in locations likely to intercept rodents. In addition, remove and discard the old bait, wipe or brush out the interior of the station, add new rodenticide according to the approved rotation chart.
• Take a tour of the facility, inside and out. Make note of areas that accumulate trash or hold seldom used items, such as drums, pallets, sacks, pails, boards, cardboard, old motors, etc. Take measures to remove, discard or properly store as many of these items as is practical. Provide bait placements near the remaining harborage areas