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If you suspect that there are bees in your chimney, do not start your fireplace under any circumstance. Beeswax is highly flammable, and you may risk an explosion if you turn it on. Even if a major blast doesn't occur, the hot wax may eat through your grout and masonry, potentially causing extensive damage. On top of that, bees are good for the environment! You may be able to have them peacefully removed without killing any bees in the process. If you see dead insects in the pit of your fireplace or there are bugs flying around your chimney, see if you can confirm that they're bees. Bees always have fur, while wasps and hornets have smooth exteriors. In addition, hornets and wasps have longer, thinner thoraxes while bees tend to be round. If you have hornets or wasps in your nest, call an exterminator and seal your chimney immediately. Hornets and wasps can be very aggressive towards humans, and if they think your home is their home, you could have a nasty situation on your hand. If you have an allergy to bees, do not get close to them. Bees are typically non-aggressive, but they may sting if they think you're trying to harm them. Rent an infrared camera from a construction supply store. Turn the camera on and point it at the fireplace. Slowly raise it up towards your roof while monitoring the screen. If there are lots of little dots flying around, you have bees. If there is a large, white mass on the screen, you have a hive. An infrared camera will cost around $50-80 to rent for a day. If the bees haven't established a hive, it will cost considerably less to have the bees removed. The contractor will likely use a vacuum to extract the bees and take them elsewhere. This will usually cost anywhere from $50-200. If you have an established hive, it will cost a little more. The contractor will need to use a grinder to cut the hive out and remove it. This can cost $200-1,500, depending on the size of the hive and the chimney. Get an inflatable chimney plug from a construction supply store. Inflate the plug halfway by blowing into the tube. Then, slide it up the pit until it's at least 1ft (30cm) above the base of the chimney. Next, blow it up as much as you can to expand the plug and block the chimney. This is the best way to keep bees, wasps, or hornets from flying down into your home. The damper, which is the hatch that closes the opening to the chimney, is not nearly enough to keep bees out. They can usually squeeze through the opening between the plates. Chimney plugs are also known as balloon plugs. Alternatively, hold a contractor's bag over the chimney and press long lengths of duct tape into the seam where the bag meets the masonry. Then, add more tape along the groves in the grout so it overlaps the seam where the first layer of tape meets the masonry. Do this 2-3 times to create an airtight fit.
Keep your fireplace off if you suspect you have a bee problem. Confirm that you have bees by looking for fur and round thoraxes. Use an infrared camera to determine if they've established a hive. Plug your chimney if it's open to keep the insects from coming inside.