What is the scratching sound coming from my air vent?

Author: Prof. Laurel Swift Jr.  |  Last update: Friday, May 29, 2026

If you hear scratching or scuttling noises from your air vents, small animals, insects, or rodents may have made their way into the ductwork. They may be nesting, foraging for food, or attempting to escape, causing these distinctive sounds.

Why do I hear scratching in my vent?

There is another unpleasant noise that your air ducts can emit. This sounds like something or someone is scratching on the metal walls of the ducts – and there is a very likely chance that this is squirrels, raccoons, rats, or other animals that have found their way into the system.

What do rodents in vents sound like?

When mice are in your vents, you'll hear scratching, crawling, or scurrying on metal in the walls, ceilings, or floors where your ductwork is. You might also hear occasional squeaking noises.

How do I get rid of rodents in my air vents?

Identifying and Removing an Infestation

Homeowners should instead locate each vent in their home and remove the grates. By placing baited traps at each point of entry, you can attempt to lure and trap mice out of the vents and prevent them from dying in the ducts.

Why is there a weird noise coming from my air vent?

A whistling or roaring sound from a supply air vent could mean the vent has either too much air flowing through it or the volume damper inside the vent is partially closed restricting the normal airflow. Homeowners often close vents in empty rooms so they don't spend money to heat or cool unoccupied space.

5 Common AC Noises and What They Could Mean

What animal could be in my vent?

Mice and Other Rodents

But on occasion you may be dealing with squirrels or even rats. There are a number of ways they may have gotten into the ductwork. But they started their journey to the ducts by entering the house first. Once in the house they may have entered the air ducts via the HVAC unit in the basement.

How to get animals out of vents?

You'll have to turn off your HVAC system and remove all the vent covers. You'll need to load a trap for each vent. Most do-it-yourself-ers use snap traps baited with peanut butter, meat, or cheese. Place the trap just inside the vent and wait.

How do you tell if mice are in your vents?

Irregular Noise: When mice run through the ductwork, it creates noises that you should be able to hear, especially during nighttime. You may also hear chewing noises, mild squeaking, and scratches. Foul Odour: When mice urinate, it leaves an odour.

What are the symptoms of the hantavirus?

What are the symptoms of Hantavirus Pulmonary Syndrome? Symptoms begin one to eight weeks after inhaling the virus and typically start with 3-5 days of illness including fever, sore muscles, headaches, nausea, vomiting, and fatigue. As the disease gets worse, it causes shortness of breath due to fluid filled lungs.

Can a rat get through an air vent?

Rats, equipped with sharp teeth, are not only adept at gnawing through air vents but can also cause damage to plastics, woods, and even metals.

Why do I hear scratching in my walls but no droppings at night?

What Is That Scratching in My Walls at Night? If you hear scratching in your walls at night, it could be mice, rats, squirrels, raccoons, bats, termites, carpenter ants, or roach colonies. By far, the most common nighttime wall-scratchers are mice, and they're most likely the pests who are disturbing your sleep.

How to tell if an animal is in an air duct?

Identifying Signs of Animals in Your Air Ducts
  1. Strange noises: Scratching, scurrying, or squeaking sounds from your air ducts are often one of the first signs of an infestation. ...
  2. Foul odors: If you notice unpleasant odors coming from your vents, especially when your HVAC system kicks on, you might have animals in there.

What could be crawling in my vents?

Air vents that aren't properly sealed off can be attractive entry points for rats, mice, and other rodents. The smaller the rodent is, the more places it can roam about your home without being spotted. If you notice rodent droppings but can't find them, you may have some rodent residents in your air ducts.

What is the random scratching sound in my house?

Your first thought upon hearing a scratching noise from your walls is that you must be in a horror movie, but when that feeling subsides, the real problem becomes clear: you likely have some sort of animal infestation. These noises are most likely caused by either squirrels, mice, or rats.

How do I stop my vents from making noise?

These are some simple ways you can stop ductwork noise:
  1. Clean or Replace the Filter. ...
  2. Clean the Ductwork. ...
  3. Adjust or Upgrade the Dampers. ...
  4. Insulate Your Ductwork. ...
  5. Check Your Furnace. ...
  6. Change the Blower. ...
  7. Install Ducts with an Insulated Liner.

What does it mean when you hear scratching?

Rats and Mice

Listen for scratching or skittering sounds in your ceiling. If you hear scratching sounds in your walls, knock on the area and listen. If the scratches stop for a few minutes before resuming, you may be dealing with rats in your walls.

Will I survive hantavirus?

Humans can contract the disease if they breathe in the virus, or if they are bitten by an infected rodent. HPS has a mortality rate of 38%.

What are the symptoms of Lcmv?

Symptoms of LCMV infection are similar to those for influenza and include fever, stiff neck, a lack of appetite, muscle aches, headache, nausea and vomiting and occur 1–2 weeks after exposure to an infected rodent. The symptoms may be much more severe in pregnant women and people with a weakened immune system.

What states have had hantavirus?

In 1993, an outbreak of severe respiratory illness in the Four Corners region of the United States (defined by the shared borders between the states of New Mexico, Arizona, Colorado, and Utah) made national headlines.

Why do I hear scratching in my vents?

Animals like squirrels, raccoons, and rodents can find their way into your house and into the ductwork. They can even make a new home in the ducts, which becomes a serious problem for your home. If you think you hear scratching coming from your ductwork, it's incredibly important to call professionals right away.

How to get rodents out of vents?

Unscrew and remove the grates that cover your heat vents. For each vent, bait a snap trap with the fragrances of fetching foods, such as raisins, dates, cheese, chocolate or peanut butter. Place a trap in each air duct. If you can spot any trails of mouse prints or droppings, place the trap directly along those lines.

What smell do mice hate?

The strong scent of peppermint is overwhelming to mice. Similarly, essential oils such as eucalyptus oil, bergamot oil, clove oil, and cinnamon oil are potent in keeping mice at bay. One study noted that eucalyptus oil applied once a day was more effective as a rat repellant than once a week.

Why is there a weird sound coming from my vent?

A gentle humming or clicking is normal, but loud rattling, banging, buzzing, or whistling means you may have a problem requiring professional help. Some factors that cause excessively noisy ducts include dents or damage, loose metal parts, dirty or blocked vents, and closed dampers.

What do mice in vents sound like?

As mice travel through a home's ductwork, they're likely to make noises. Scratching, squeaking, and even gnawing can be heard when these rodents are occupying heating ducts.

How do you remove rodent from air ducts?

Steps To Take If Rodents Are In Your Air Ducts
  • Take Time Outside of the Home. ...
  • Inspect the Inside and Outside of Your Home. ...
  • Turn Off Your HVAC System. ...
  • Collect the Necessary Materials. ...
  • Remove the Vent Covers. ...
  • Set the Traps. ...
  • Check the Traps Daily. ...
  • Remove the Intruder.

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