Do Bats Come in Through Fireplaces?

As a home improvement expert with over 10 years of experience, I often get asked by worried homeowners – "do bats come in through fireplaces?" If you‘ve heard odd noises or caught sight of bats around your chimney, you may be wondering the same thing.

While it‘s relatively uncommon, bats can and do find their way into homes through fireplaces on occasion. Read on as I break down everything you need to know about bats entering through chimneys and fireplaces, from how they gain access to tips for keeping them out for good.

How Can Bats Access a Home Through the Fireplace?

Bats are crafty creatures that can take advantage of even the smallest gaps and crevices thanks to their tiny size. According to bat removal experts, the average bat needs only a 1⁄4 to 1⁄2 inch opening to squeeze through. Here are the main ways bats can enter your home through the fireplace:

Gaps in the Chimney

The most common point of entry is through small gaps or cracks in the chimney structure itself. As a chimney ages, the mortar between bricks can weaken and begin to crumble, leaving perfect narrow passages for bats to crawl through. These small openings are usually found near the top of the chimney.

Loose or Missing Chimney Caps

A chimney cap is designed to prevent water, debris, and animals from falling down the flue. Without a snug fitting cap secured in place, bats can easily fly right into an open chimney.

Open Damper

If the fireplace damper is left open when a fireplace is not in use, bats can simply fly down the flue and gain access to the firebox.

Gaps Around the Firebox

Loose mortar or small holes where the firebox meets the exterior wall can also allow sneaky bats entry if they find these gaps.

Nearby Trees

Large trees growing too close to the home provide roosting spots for bats. From there they can easily fly over and scout out nearby chimneys and other openings.

What Bat Species Commonly Enter Through Fireplaces?

According to bat control specialists, the three bat species most often found roosting in chimneys across North America include:

• Big brown bats – They use echolocation to find prey and roost in colonies up to a few hundred.

• Little brown bats – Also called little brown myotis, these bats roost in groups of up to 300.

• Mexican free-tailed bats – Colonial bats that live in very large colonies of up to 250,000 members in caves or under bridges.

However, other bat species may also find their way inside, depending on your geographic location.

Signs of Bats Roosting in Your Chimney

As a homeowner, how can you tell if uninvited bats have moved into your chimney? Be on the lookout for these common signs:

Noises in the Chimney

Listen for high-pitched chirping or scratching sounds coming from inside the chimney, especially near dusk when bats become active. You may also hear fluttering wings as they fly about.

Droppings Around the Fireplace

Look for distinct, dark brown or black bat droppings around the fireplace opening and hearth. Bat droppings resemble dark rice grains, while rodent droppings look more fibrous.

Bat Odor in the Home

Get a whiff of a slightly musky, ammonia-like odor wafting from the fireplace. This scent comes from bat urine and guano.

Visual Sightings

You may see bats exiting the chimney flue at dusk or returning at dawn. Night vision or motion-activated cameras can help confirm bat activity.

Bat Staining on the Chimney

The ammonia in bat urine can cause a brownish stain on the exterior bricks of the chimney over time.

If you spot any of these signs, it likely means a colony of bats has settled into the chimney. Don‘t delay – contact a qualified bat removal professional right away to evict your unwanted visitors before the problem worsens.

Health Risks of Having Bats Roost in Your Chimney

While most North American bats don‘t attack or bite humans, their presence comes with some health concerns you should take seriously:

Rabies

Less than 1% of bats carry rabies, but since it is nearly always fatal in humans once symptoms appear, any bat exposure warrants rabies treatment.

Histoplasmosis

Bat droppings promote the growth of Histoplasma fungal spores when inhaled, which can cause flu-like respiratory illness in humans.

Other Diseases

Bats can also transmit other diseases such as SARS, henipavirus, and salmonella. Their guano and carcasses allow mold to grow within chimneys as well.

To avoid potential disease transmission, it is vital to avoid direct contact with bats and their droppings by hiring professionals for safe removal and proper personal protective gear.

Additional Risks of Having Bats in Your Chimney

Aside from health hazards, allowing bats to roost in your chimney can also lead to other problems:

• Fire hazard – Dry bat guano easily ignites and increases fire risk. Large amounts of feces can ignite due to excessive heat in the chimney.

• Structural damage – Corrosive bat urine and guano can degrade mortar and erode chimney bricks over time.

• Pest infestations – Cockroaches and other pests feed on bat droppings and can spread to the home.

• Contamination – Bat parasites like mites, fleas and flies may also enter the living areas.

• Noise issues – Loud squeaking and scratching noises from bats in chimneys can disrupt sleep.

To avoid catastrophic property damage or dangerous fires, chimneys used by bats should be cleaned and disinfected once the bats are removed. Be sure to have your chimney inspected by an expert each year.

How Can I Prevent Bats From Entering My Chimney?

The best offense is a good defense when it comes to keeping bats out. Here are some proactive exclusion methods I recommend to homeowners:

Install a Stainless Steel Chimney Cap

A quality chimney cap with stainless steel mesh and a small mesh gap size (1⁄4 inch or less) will effectively block bats and other wildlife from entering the chimney.

Use Chimney Balloons or Chimney Tubes

Inflatable chimney balloons or bendable chimney tubes can be inserted into the flue during months when the fireplace is not in use. This creates a physical barrier to keep bats out of unused chimneys.

Seal All Possible Entry Points

Thoroughly inspect the exterior of the chimney and fireplace for any small gaps or openings. Use high-grade sealant, mesh, caulk, or cement to seal up potential entryways for bats. Copper mesh works well.

Install Vent Covers

Place vent covers over all external fireplace and chimney vents and openings. Be sure the covering has 1⁄4 inch mesh screens or smaller to block bats.

Manage Nearby Trees

Trim back tree limbs, branches, and vegetation growing close to the chimney. Otherwise they can act as "jumping off" points for bats to access the roof and chimney areas.

Use Fireplace Dampers

If you have an accessible damper, keep it fully closed when the fireplace is not in use to seal off the chimney. This helps deter bat colonization.

Conduct Regular Chimney Inspections

At least twice per year, visually inspect your chimney and fireplace for any signs of animal intrusion, new holes, or loose mortar that could admit bats. Seal any gaps right away.

Close the Damper Before Vacations

Plan to close the fireplace damper before going away on vacation for an extended period. This will keep bats or debris from entering while you are away.

As you can see, there are several effective methods for protecting your chimney and home from bat infiltration. With some diligent prevention and regular inspections, you can help ensure bats don‘t become an unwelcome reality in your cozy fireplace.

What Should I Do if Bats Are Already Roosting in My Chimney?

If you discover bats have already moved into your chimney, please do not attempt to trap, poison, or otherwise remove them yourself. Here are the safest and most responsible steps to take:

Avoid Direct Contact with Bats

If you happen to spot bats flying from the fireplace into your living space, resist the urge to swat at them or grab them with a towel. As mentioned earlier, even healthy bats can transmit rabies through bites or scratches.

Contact Professional Bat Removal Services

Licensed bat removal experts have the proper rabies vaccinations, protective gear, permits and training to remove your unwanted bat colony safely and legally. They also know proper exclusion techniques to guarantee bats don‘t return after eviction.

Have Your Chimney Cleaned and Disinfected

Once the bats have vacated, have a chimney sweep scrub and disinfect the entire flue from top to bottom. This will clean out guano deposits and get rid of any lingering organic odors.

Repair Any Structural or Pest Issues

Work with a chimney repair specialist to fix any gaps, holes or spalling damage caused by bat guano. A pest control professional can treat for any bug infestations resulting from the bat colonies as well.

Install Bat Houses

Giving evicted bats a new place to live reduces the odds they will attempt to re-enter your home. Having a wildlife specialist install one or more bat houses at a safe distance from your home provides alternative roosting opportunities.

Bat removal and exclusion takes patience, but with the help of qualified professionals, you can reclaim your chimney and prevent new colonies from forming. For more tips on controlling wildlife pests, contact my team today.