If you have noticed bats and bat droppings (bat guano) close to your home, then it could be that you have a colony of bats nesting in your attic. The usual habitats for these wild animals are caves and woodland areas but as many have been destroyed, more and more bats are forced to roost in areas alongside humans.

Diseases Associated with Bats

By far the main issue when it comes to bats as opposed to other pests is not so much the damage but more so the risk of disease transmission from bats to humans. When bats start to inhabit human environments the risk of a potentially fatal disease being passed to a human is real and, therefore, needs addressing. The diseases most commonly associated with bats are histoplasmosis and rabies.


Histoplasmosis is a respiratory disease that is caused by the fungus Histoplasma capsulatum, which is found in bat droppings. The fungus produces spores that when they become airborne can infect humans by inhalation alone. Symptoms of the disease can be flu-like, to begin with, and also affect in vision, hearing, and the heart’s performance. The illness may further develop into a fever, blood abnormalities, pneumonia, and even death.


By no means do all bats carry the rabies virus, but a small percentage do. When rabies has infected a bat it will make it very sick and so any bat that you encounter flying about could possibly have rabies, though the chances are low.

Bats do not generally attack humans but may attack if humans attempt to capture or handle them, especially if they are rabid or sick. If you or your pet has been bitten by a bat, in particular, a sick bat, you should attempt to catch the bat with tongs, preserve it, and get medical assistance immediately. There is a rabies vaccine that can be effective if given prior to the onset of symptoms; however, once symptoms start to show, the disease is nearly always fatal. In fact, there have been only six known survivors of the rabies virus.

What You Shouldn’t do if You Have a Bat Colony

If you have bats inside your attic, you may be tempted to kill these wild animals but this is not an option you should choose. These important and sometimes protected creatures are also a benefit in many ways as bats feed on unwanted insects such as midges, flies, and mosquitoes.

Exterminating a bat colony at the wrong time of the year could lead to infestations and issues with other pests. In fact, many people encourage bats to shelter near their homes to provide a natural control of other pests. A recent study found that one bat alone was capable of consuming 600 mosquitoes in a single day.

The bats that nest in your attic are nearly all female bats. They will roost in your attic and give birth to one or two pups around June or July. You should note that attempting to kill newborn bats is not just inhumane but it is illegal. Do not attempt to kill bats during summer months when there are bat pups that cannot yet fly. If you take measures to kill bats during this time the bat babies will be left to starve and dehydrate in your attic, the corpses will then become a serious health hazard as well as attracting other dangerous pests. Also, you should avoid direct contact with bats, especially if one is acting strangely as it could be a rabid animal.

What Should You do if You Have a Bat Colony

If bats have entered your attic, then you need to take careful and strategic action. In order to rid yourself of nested bats in your attic, all you need is a little time, patience, and know-how.

Once it comes to late August or early September, female bats will be ready to leave your attic with their pups and will be heading to nearby caves to hibernate. All you need to do is spend a little time observing your roof and attic at dusk.

This is the time of the day when bats will start to leave the nest and come out to hunt and feed during the nighttime hours. Simply make notes of the holes the bats are using to exit and enter.

When all the bats in the attic have left for the winter, now is the time to act.

With the bats in your attic all safely gone for the winter, all you need to do is fill in the holes in the roof that the bats have used to gain entry. It is best to use an epoxy sealant to ensure that the holes are weather-proof to prevent damage to your home. Bats are not able to create holes in your home like other pests so filling in a hole will do the trick in terms of an eviction; however, the bats will return next year.

Returning Bats

Bats depending on the species can live up to 30 years and they return to previous nesting areas faithfully each year. When bats return to your home after you have filled in holes they will start looking for alternative areas to nest and bring up their young. Your efforts may result in another person’s problem as bats inhabit other local homes and buildings, instead.

Without bats in the neighborhood, you could also be overrun with mosquitoes and other nasty insects.

By far the best thing you can do is to provide your recently evicted bats with a new home in the form of a nesting bat box and co-exist safely. Bat boxes are approved by conservation experts and can be easily and cheaply installed in your yard. By using a specially designed bat box you will be eliminating the risk to human health of nesting bats and the diseases they carry as well as the odor from their droppings while still benefiting from bats consuming troublesome insects.