Bats are removed from the chimney with a live exclusion. This is the best way. It is the most effective, and the only legal way, as well. A live exclusion means that you install a one-way door or one-way netting devices which allow the bats to exit the chimney freely, as they do each night, but then not get back inside. It's a simple concept, but it's difficult to execute effectively. Bat removal requires adherence to state laws protecting bats. For example, never perform a bat exclusion during the summer, because of the flightless baby bat pups in the chimney! I myself trained in bat removal for two years, and still needed a fair amount of practice to perform bat removal correctly. Our network of wildlife removal professionals on this site are excellent in bat control. Read more about how much does bat removal cost.
Do two crucial things: inspect inside the chimney to identify bat species and colony size, and watch the outside of the house at dusk, to see where they are flying out.
If there are any other areas other than the chimney to address, do so. It's best done at night, with a light, for better vision.
Set the bat exclusion funnels or netting on the top of the flu, which you left open Observe for 3 nights, to make sure the bats can get out but not back in!
What to do about bats in the chimney - Your fireplace is supposed to be a great family gathering place where you can not only sit and talk, but also keep warm. It is such a great centerpiece that during the winter it becomes the primary place where the family comes together to talk or watch television. Not to mention it is the most romantic of places to be able to enjoy a cozy evening with that someone special. This makes the fireplace a prime location in your home.
Of course the chimney may also be a prime location for other animals to decide to gather. Raccoons and squirrels like to make homes in people's chimneys, especially during summer months when the fireplace is not used. They can build a little den there and basically enjoy a nice place to roost without having to be disturbed.
But these animals are not the only ones who see the benefit of your chimney. Bats have also been known to make a home in a person's chimney and, when they do, this can turn your home into a nightmare. Bats carry diseases and are quite noisy, ruining the peace and safety of your home, but what to do about them? That is a good question.
The first thing to do is to avoid doing that which seems obvious. The first thing that many think would be a good idea would be to start a fire in the fireplace, open the flume and let the smoke, heat and flames scare them away. Honestly...really terrible idea. Consider that not only may the bats simply fly into your home, but you may have a burning bat flying into your home setting your house on fire. This is why this is the mother of all bad ideas.
Others try putting repellants down the chimney and scaring the bats away this way. This can be an effective tool depending upon what kinds of repellants you use. You want to make sure that whatever you use is not toxic to you or your pets. Consider that this may be in your chimney for a few days and you don't want those fumes entering your home. Also make sure that you put the repellant in near dusk. Bats are nocturnal so they will be more likely to leave during the early evening.
Also consider using noise and light. This will work to make them feel like their home is not a great place to be anymore. You want to do this at dusk as well so that they will likely leave your chimney for the security of the darkness.
Other bat information:
Bats in a tile roof: risks and removal process
How to get rid of bats in the chimney - they are not so easily just "gotten rid of". But they can be properly and effectively removed, and the problem can be prevented from happening again. Remember to follow the steps above, whether you do it yourself or hire a professional to do it for you. It is not easy work, but if you don't remove the bats in your chimney, they will go on to cause further damage. When you do decide to remove them, please remember to treat the animals with respect, and take the work seriously. You can get rid of bats in the chimney if you follow the correct approach. Best of luck!