What type of insulation helps deter rats?

Old 03-06-16, 07:05 PM
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What type of insulation helps deter rats?

What type of insulation is a rat's least favorite insulation... i know that no insulation is 100% rat proof but surely different types of insulation keep them out more or less
Old 03-06-16, 07:27 PM
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Roxul would be the least rodent friendly..... except maybe for cellulose.
Old 03-06-16, 07:34 PM
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Mice love all types of insulation equally. I don't know that spray foam was tested in the study below since it was not popular when this test was done, but I would imagine it would be similar to polystyrene.


IMO spray foam would be your best bet, but poison bait stations should probably be used in the attic to help control the number of unwanted house guests.
Old 03-07-16, 03:42 AM
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Any air permeable insulation will allow them to detect what is on the other side and then they will go right through it. I've seen plywood where I suspect there was a small gap that provided the motivation for them to design their own door.

Your defensive steps should start on the outside with traps and bait (if allowed) before they get inside. Then, I like to have traps where I can see them easily to know when they have located a new entrance. Rats are rare here but mice are everywhere and they will keep looking until they find a weak spot.

Wherever you are looking to install the rat proof insulation, it needs to be either enclosed on all six sides, air tight, or have a wire screen covering that they cannot get through.

Old 03-07-16, 05:55 AM
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While cellulose insulation is less mouse / rat friendly than other insulation choices, I don't believe it will "deter rats". But, even if it did, what does that really mean? If, for example, you put insulation in your attic that is not rat friendly, I can't imagine the rats leaving your building; they would just go elsewhere. After all, rats don't go into your building because of the insulation.

Eliminating rats is a 3 pronged approach:
  • Stop entry,
  • Eliminate food sources,
  • Kill what remains.

If you have enough rats to consider insulation options (and 1 is too many), entry is no longer an issue and I suggest focusing on killing first. Make it a multi-pronged attack with more than one poison and a variety of traps. There are techniques for maximizing trap success and I'd look into those.

Finally, are you talking about crawl space?

Last edited by Tony P.; 03-07-16 at 06:18 AM.

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