Because they need water daily they tend to nest where water is readily accessible.
Rodent in attic and ducts.
Heating and cooling ducts form the core of this rodent highway.
Roof rats aka black rats often build nests in attics.
Even if none of the pests have died and started decomposing you may smell a pungent odor.
If mice have invaded your air ducts the following steps can help you end the problem.
All kinds of critters including mice can enter through crawl spaces under buildings or even foundations on slabs.
Still the rodents will be looking to nest for extra protection and warmth.
Count the number of heating vents in the house.
The way most wildlife control operators or pest control companies remove these rodents from your ductwork is through manually inner in the ductwork from either the attic or the crawlspace and physically removing the animal with either a glue board or a control stick sometimes the rodent can be lured out of the duck work with a baited trap or other sent type of attractant but if the animal is in fact stuck the only way to get the animal out is to physically remove the animal from the duck work.
Droppings chewed up materials in the area and bad smells indicate you have an infestation.
Once you discover you have a problem with rodents in your ductwork the issue may already be too far gone.
First you will notice a significant mess around the ducting.
Special precautions need to be taken when the heating ventilation and air conditioning ducts become infested with mice.
This is where your precious attic insulation comes in.
When rodents infest your attic they have already hit the jackpot so to speak.
How to get rid of mice in heating ducts.
Inspect the heating ductwork for holes.
Mice often use the dark corners of the home from fireplaces to exhaust vents to attics as their own personal transit system.
This odor indicates rodents have been urinating in your ducts.
Presumably your attic is dry and relatively protected from the elements that would otherwise bring in moisture.
You can also remove the vent covers and look inside your ducts.
Cover these holes with duct tape.
Bait as many mouse traps as there are heating vents.
When mice die in the heating and cooling ducts it can send a rank odor throughout a house.
These are the entry and exit points for the mice.
Insulation spray foams tapes and other synthetic seals or collars are not absolutely rodent proof either.
Speaking of dead rodents in your vent a foul smell emanating from your ducts is another sign you might have an infestation.