The presence of bats in a property or a house is a nuisance that nobody wants to face. They can easily enter a property, live in large colonies, leaving behind large amounts of

droppings and urine, and can even act as carriers of various disease-causing pathogens.

Close up of Flying Pipistrelle bat
Close up of Pipistrelle bat (Pipistrellus pipistrellus) flying on attic of church in darkness

Where do Bats Prefer to Live?

Bats prefer secluded, dark areas where they are safe from harsh weather conditions and predators. Bats typically roost at high places, such as attics. They can enter a property through a crack or orifice as small as 5 inches, usually near chimneys. They can even travel through pipes or walls looking for a suitable place to live. If you tend to find a single bat somewhere in your house, it is likely that you have an entire colony living in your house.

Bats are really quiet creatures. You might not find out that there are colonies of them in your home until they have been there for a while.

Signs of a Bat Infestation

An obvious sign of bat infestation is the presence of a guano in the house. Bats leave behind fecal droppings at the entrance to the roost area that can stick on walls, porches, windowsills, or on regions below the entrance to the roost. Guano is similar in appearance to mouse droppings however, they can be larger in size. Check your porch and attic for droppings. You might also observe bat urine strains on the ceiling or walls.

Bats are nocturnal in nature and leave the roost to hunt at night. You will hear scratching or light squeaking sounds coming from the attic, walls or chimney as they crawl out of the roost at sunset and return at sunrise. Since bats tend to be quiet, therefore you might not hear them unless a loud noise scares an entire colony of them.

You might observe rub marks on the outside of your home, especially around areas with holes or cracks. Bats leave such marks when they enter or leave a property.

If you tend to notice any one of these signs and want to get an accurate estimate of how many bats are residing in your home, you can search for them at night. Sit outside your house and wait for the bats to leave at dusk. This will also help you figure out where their entry and exit point is.

People are often frightened of a bat stuck in their basement, attic or a back bedroom. Finding bats inside your property is not a pleasant experience. However, this is really common.

Colonies of bats can become extremely large. Since they tend to sleep all day long, it can be difficult to know for sure if you have a bat infestation. Following are a few things that one should be aware of:

Finding a Bat in Your House

Bat colonies roost especially in places that are situated high up, such as in an attic. However, occasionally, a couple of bats will follow a small wall cavity or a pipe in order to find a space to sleep.

Hearing Bats Fluttering in Your Walls

Bats are nocturnal with respect to their feeding habits and tend to leave their roost at night-time to feed. You are likely to hear bats only if they are residing in your walls, or when an entire colony gets disturbed due to some loud noise. 

Bats make screeching noises and you might hear them scratching and crawling at dawn and dusk when they wake up or return to the roost. In some cases, people can have more than 600 bats living in the walls of their houses but the only time they could be heard was when the refrigerator door gets slammed or somebody pounds on the wall to wake them up. This indicates that they are way quieter than one would imagine.

Bat Droppings on Walls or Windowsills

Bats are a species of habit. They tend to roost together at the same place every year. Another thing you can count on is that these winged mammals leave fecal droppings on the exit and entrance points to their roost area each night. These droppings accumulate on a windowsill, wall, porch, or other places exactly below the place from where the bats enter your home. Bat droppings, known as Guano, resemble mouse droppings. Thoroughly inspect the windows in your attic for visible droppings. Also, check out any obvious orifices on the outside from where bats are getting in and out. It is likely to be up high. However if the bat colony tends to be large, then the guano will be hard to miss.

Should Bats be Left Alone? 

Legally, bats are protected under British law, therefore destroying a bat colony in order to build a house could land you in big trouble. But that’s not all. Besides being protected by law, there are several other reasons why bats should be left alone in peace.

  • Bats and Science

Bats are a very diverse species. They are the second largest number of species in the order Mammalia, with rodents having the largest number of species. This diversity provides great insight into how different species acclimatize to various habitats and come to occupy different niches. This also highlights vital parallels with animal behaviors from other classes and orders.

They are also crucial in the primary way that a number of microbats navigate, communicate and effectively visualize their environment through echolocation. This means that they are always giving out valuable information about the way they understand, perceive and communicate with the world. This provides unique data to scientists and researchers all around the globe.

  • They Consume Dangerous Insects

Bats are known to feed on mosquitoes. This is an incredible ability they possess because mosquitoes, being the carriers of the West Nile virus and Malaria, are the single biggest killer of humans across the globe. Not only the mosquitoes, but bats are also known to eat the moth Helicoverpa zea. This is a prevalent pest that destroys a number of important cash crops. Therefore, anything that protects both our health and our food has to be worth conserving. 

  • They Tell Us A Lot About Evolution

Paleontologists reveal that these winged mammals have a very limited fossil record. The reason being that their skeletons are very thin and light to support easy flight. Regardless, there are a few things we know about them that are very odd. Such information indicates that understanding bats’ place in the evolutionary timeline might help a lot of other things fall into order as well.

To begin with, despite their overall rough appearance, they are not rodents. In fact, they are more closely related to cats, dogs, horses and even dolphins and whales than they are to hares or rodents. The oldest bats known to science are about fifty million years old, and they have proved that flight was developed much before echolocation in bats. Also, a tooth similar to that of bats, from the late Cretaceous era indicates that there is a lot more amazing stuff left to be discovered.

  • British Bat Species are Endangered

This is one of the greatest tragedies. British bats may not be quite as lovely or photogenic as their large flying fox cousins in other regions, however, they are equally crucial to the biodiversity and proper functioning of the British ecosystem. Even the most typical of British bats, such as the brown long-eared bat, are hardly prevalent in the UK, and the rarest species have only a single known remaining bat. An example is of the Greater mouse-eared bat, which was long thought to be extinct. Therefore, losing even one bat species will drastically impact the ecosystem.

  • One of a Kind

As the only mammalian creatures with the ability for true flight, bat species are incredibly amazing. Moreover, their ability to echolocate for hunting for food is quite unique among terrestrial mammals.

Bats are given legal protection by both international and domestic law in Britain, so even if you aren’t that fond of bats, damaging or removing their roosts is a bad idea. Implementation of law restrictions like these are usually quite obvious and clear-cut, therefore ignoring them could easily land you in serious trouble with the law agencies.

Are Bats Harmful?

Bats are not known to attack people. Scenarios in which they have been reported to attack are usually related to incidents where bats fly near people outdoors during summer, or near people in swimming pools while they dive in for a drink, or when insects are present in abundance around us.

Bats feed on mosquitoes and insects. However, bats, along with a number of other mammalian species, act as a carrier of rabies. This means that there will almost always be chances of the rabies virus being present in bat colonies. Despite that, bats themselves don’t get infected by rabies, owing to their strong immune system. 

A huge majority of bat species do not become rabid. Also, there is no significant evidence of epidemic outbreaks in bat populations. This is because when bats do become infected with the rabies virus, they eventually die from the disease. Rabies can only cause disease symptoms only if the virus enters the central nervous system through mucosal membranes such as mouth, eyes or nasal passages; or through a bite wound.

The virus does not spread through contact with urine, fecal droppings (guanos) or blood. It does spread through contact with the central nervous system tissue or saliva. The virus is usually contracted through the bite of a rabid animal.

Getting Rid of Bats

To effectively get rid of a bat infestation, you need to assess the situation thoroughly. Listed below are some things that you should take into consideration for this.

  • Where are the bats roosting?

Are bats inside the property or under the roofing or some other structure on the outside of the house? Bats can be found roosting in several parts of a house structure such as under the ceiling, fascia boards, siding, flashing and rafters, in cracks and crevices of the walls or chimneys, under a porch roof or behind shutters. Sometimes bats may appear to be roosting inside the house, when in reality they are simply under the fascia or the roofing, and may not cause significant problems for the homeowner. 

  • How protected is the building? 

Are there lots of crevices and cracks in the property which allow easy entrance to the building space? In some types of houses, such as log houses, cedar shake roofs, and A-frame houses, the exclusion is very difficult. It is a more realistic approach to exclude bats from a certain part of the property and let them reside in some other portion.

  • Is it a night roost?

Night roosts are areas that bat colonies use temporarily during the night-time in order to rest between their feeding periods. Night roosts are usually open spaces, such as archways above doors, under bridges, carports, and covered patios. Homeowners are less likely to see bats at night roosts however they might observe fecal droppings in the morning. The biggest problem with night roosts is cleaning up the feces every morning. However, since bat feces make an amazing fertilizer, it can be used in the garden. 

Also, you could place a plant pot where the droppings usually fall in order to avoid having to manually clean the feces or place a gutter or shelf along the wall under the night roost to easily catch the droppings before they fall.

The presence of night roost does not always indicate that there are colonies of them inside the property. Also, the limited use of a night roost is not always a major problem. Use of deterrents such as garlic bulbs, mothballs, owl statues, and ultrasonic devices are ineffective. There are a number of methods that can prove to be much more effective in deterring bat colonies from using a night roost, some of which are listed below. 

  • Keeping the area brightly lit.
  • Setting up a fan that blows on the wall where bat colonies usually roost.
  • Hanging flashing, orchard tape, mylar strips or balloons of tin foil that are able to move along with the wind.
  • Applying a slippery material, for example, plastic sheets, with the walls where bats frequently come to roost in order to limit their ability to cling with ease.
  • You can also use aerosol cat and dog repellents in a particular area. Make sure to apply the spray when bats are not there. You will have to re-apply regularly to keep bats off your property.

  • What Bat Species is Present?

Correct identification of what species are present in the property can guide you about eviction or exclusion timing and techniques. The most commonly found species in the buildings include Little Brown Myotis, the Big Brown Bat and Yuma Myotis. The rare species of Townsend’s Big-eared Bat can also be found in buildings. It is much easier to identify because it has long distinct ears and the ability to roost in large groups on rafters in very open areas. This habit makes them predisposed to disturbance or injury by human activities, either through accidental or intentional means. Long-eared Myotis, Long-legged Myotis, Californian Myotis, Pallid Bats, and Northern Myotis are also known to use buildings but are not typically found as often in similar roost types. 

If you observe bats with a layer of white fungus on their wing or nose membranes then immediately contact your community bat project or a local provincial government wildlife biologist as soon as possible. This condition is caused by a fungus called Pseudogymnoascus destructans. This disease is known as a white-nose syndrome and it has lead to the extinction of a number of bat species.

  • Inspection 

Carry out a thorough inspection to determine the entry and exit points of bat colonies. Do an inspection on a bright sunny day to search for missing roof shingles, holes in soffits, eroding eaves, etc. Then take a look at the house from all sides on a warm, clear summer evening, just before dusk, observing any bat activity. In addition to this, you might observe bat tracks, distinct brown, greasy marks, around the exit and entry points.

  • Exclusion 

The exclusion process involves using tubes or netting at entry points, which will allow bats to drop down and fly however re-entry would be prevented. The excluders are kept in place for about two weeks so that the bats finally give up trying to get back in. Once they are gone, the process of sealing, plugging and caulking can be carried out.

  • Cleaning Up

The remaining mess should be properly removed, disinfected and deodorized. Bats can easily sniff out a prior niche. The droppings could contain a fungus that can cause a fatal respiratory infection called histoplasmosis in people with a compromised immune system. Even if it is a small cleanup, you must wear proper protective gear which includes gloves, eye protection, and a mask that filters particles over two microns in diameter. After thorough removal, disinfect the affected area with an antibacterial or bleach solution.

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Dusty Showers has been in the urban nuisance wildlife and pest control field since 1993. Taught by Garon Fyffe, a pioneer in humane nuisance wildlife management, Dusty has a passion for finding humane solutions to human & wildlife conflicts. Dusty was the only individual invited by the Florida Fish & Wildlife Commission in the lat 1990's to help write legislation for legal protection of Florida bats. With an instinct for solving wildlife, Dusty found pest control to be an easy "add-on interest". Dusty started his first business "Animal Instincts Wildlife & Pest Management" in the Tampa Bay, Florida area in 1995. Eventually selling Animal Instincts in 2002, Dusty went on to start Creepy Creatures Termite and Pest Control in 2009, which he still owns and operates today in Palm Harbor, Florida.

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