Researchers have yet to discover an insulating material that will deter mice 100%. In 2011 how can this be? In 1992, the University of Nebraska in conjunction with the Extension service studied the impacts of mice on five types of insulation: Vermiculite, Cellotex, Rockwall, Fiberglass and Styrofoam. They all failed the mouse proof test, that was almost 20 years ago! But, as of this writing, I did one more quick search, just in case something was invented since I began this article (ha ha one hvac website day), I discovered I actually hvac did miss something. There is a product that advertises to be "rodent proof" which consists of a reflective type insulation, constructed with a sort of metal-ized film and nylon combination instead of the more common http://dcseo29.page.tl/How-Does-an-HVAC-System-Work-f-.htm insulation types. So I stand corrected. And, I'd like to point out, I studied the site and they used the same research materials I used in the opening paragraph; not to mention there is click here a rodent damage disclaimer on the site. So, while this new product hvac may be beneficial and perhaps better than products builders currently use, its still not 100% rodent proof. Okay, mice in the attic and HVAC, on with the show.
The older a structure the more susceptible it becomes to rodent infestation, however new structures are not immune. Insulation, spray foams, tapes, and other synthetic seals or collars are not absolutely rodent proof either. Special precautions need to be taken when the Heating, Ventilation and Air Conditioning ducts become infested with mice. All kinds of critters, including mice, can enter through crawl spaces under buildings or even foundations on slabs; they sneak through the gaps left by connections near plumbing, sewer systems, pipes, phone lines, cable lines, electrical lines, meters, fire places, chimneys, wood stove pipes, gas connections and washer and dryer vents. Ive even seen mice - all cuddly- in our circuit breaker panel. Another place to check is your HVAC condenser, mice will nest and chew wires there as well. And if the copper is exposed, get it hvac fixed now or you could have worse problems, like a fire!