Get ready for rodents before cooler weather

By Kevin Gewin

There are differences in control programs for Norway rats, roof rats, and house mice.
two rats eating

Identification is key to adopting a good rodent control prevention program 


Norway rats have a larger habitat so baiting can be spread out to cover more ground. Roof rats, as their name describes, will find harborage above ground. House mice have a much smaller habitat so bait placements should be moved closer together so you don't miss a population. Burrows, gnaw, and rub marks, as well as dropping size, help identify which type of rodent you have.

Cleanup and preparation are key components to a good rodent control program


Rodents utilize all types of nest locations and nesting material to provide for their safety. Burrows, empty walls, and attics are the most common nest locations. Grass and insulation are commonly used for nesting material. Removing all available harborage enables the use of bait stations even more.

Anything not being utilized for production purposes in and around barns should be removed. In preparation for the next step — baiting — all weeds need mowed down and a weed killer sprayed around barns to form a 2-foot zone where the rodents are in the open while trying to get inside the barn.

Baiting for rodents is the most important piece


You need to have the rodents consume a lethal dose of the active ingredient in the baits to cause death. There are many options today when choosing a bait, but I suggest either a single-feed anticoagulant or a neurotoxin. They have the best chance to help reduce your rodent population.

Bait placement is important because the bait needs to be in the area the rodent is traveling. Bait stations are useful to protect non-target animals from getting access to the bait, plus they help keep bait fresh longer.

Once you have a rodent population in check and under control, continue keeping bait in the bait stations and monitoring for any new rodent activity. As we all have seen, rodent populations can increase rapidly, so continuing with baiting and monitoring can help prevent a rodent population explosion.

Rodent control: Easy as 1-2-3

  1. Identify your pest
  2. Clean up to keep out
  3. Follow baiting basics

Common rodent pests:
house mice icon

House mice

Small all the way around with a tail as coated with fur as the rest of its body.

Droppings: pointed, average length 1/4" 

roof rat icon

Roof rat

Large eyes, large ears, slender longer hairless tail

Droppings: pointed, average length 1/2"

Norway rat icon

Norway rat

Small eyes, small ears, stocky short hairless tail

Droppings: blunt, average length 3/4"

Facts about mice and rats

  • Norway rats average 100 pups per year; mice average 50 per year.
  • Rats and mice have poor vision but excellent senses of touch, taste, and smell.
  • Mice can maneuver through a hole as small as 1/4-inch in diameter. Most rats can fit through a 1/2-inch hole in diameter.
  • Rats and mice are nocturnal, so visible activity during the day is a sign of a large infestation.

Bait station tips

  • During wetter months, check for moldy baits. Replace if necessary.
  • Pressure wash bait stations every 6 months to avoid residue buildup.
  • Keep out debris — rodents shy away from bait stations filled with debris.

About The Author

Kevin Gewin

Director, Regional Sales, Integrator
MWI Animal Health
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