I actually don t think this can be done legally.
Roof vents and rats.
Rats often enter homes and business s through vents located on the roof.
Your best bet might be to extend the duct a few feet above the roofline to make the vent inaccessible to rats.
Rats climb down and get into your plumbing system and get into your home through the toilet.
Roof rats are known by a variety of other names including palm rats fruit rats ship rats and alexandrian rats.
One common style of vent that is located on the roof is commonly called a j vent.
Animals in the attic knows where to find these holes and how to plug them.
The soil vents also known as a vent stack can let rats into your home.
What you can do here s how homeowners can help prevent roof rat infestations.
On your roof seal off openings such as vent pipes.
Use a heavy grade of steel wool copper mesh or metal scouring pads to fill cracks and holes in exterior walls.
To prevent a roof rats from nesting in your home make sure that all windows and vents are screened.
Especially on a roof where you will have difficulty getting up to clean it.
How to get rid of roof rats.
If you have overhanging trees textured walls or anything that would let a rat climb on your roof then you should have aluminum screens installed on all your soil vents.
These rodents can get to the roof from the branches of trees.
Rats can easily climb pipes rain spouts cables and other vertical objects where holes can provide an entrance to your home.
Keep trees and shrubs trimmed away from the building and cut back limbs overhanging the roof.
These entry points need to be sealed in order to prevent rats from entering the structure through roof vents.
Both roof rats and norway rats a stockier variety of rat can infest homes.
Chris cudmore oct 24 13 at 18 29.
Some ridge vent installations leave small holes large enough for a rat to enter your home.
A full sized rat can enter your home through a hole as small as a quarter.
Caulk all exterior wall cracks.
Trim all tree branches to further prevent entry.