With so many bat repellents offered up and advised on the internet, you would be entirely forgiven for thinking that the bat removal project would be an easy one. It won’t be – those repellents that you read about on the internet usually do not work. Where they do work, they don’t repel; they kill.
Ammonia, for example, is one common idea thrown around as a repellent for various pest species, including bats. We have also seen it recommended for plenty of others too – raccoons, rats, mice, opossums, skunks, snakes, you name it; we’ve seen ammonia as a way to get rid of it.
When you use ammonia, you are using the vapor that it gives off – the vapor is actually toxic. The vapor fills the air of the space that the bats are living in, forcing them to back away. In theory, it should work to force them out of the attic or whatever space they have chosen as a nest, but that’s only if you can personally guarantee that they will leave. Many of them don’t think to fly towards the exit of the roost, especially in broad daylight, and will, therefore, retreat into a deeper part of the building. If this is in your attic, using ammonia vapor will probably drive them deeper into the attic (where they are very commonly found), and perhaps even into the wall cavities or the actual living space of your home. In reality, the ammonia won’t get rid of the bats, but will instead force them to escape into a much more difficult to clear-out spot.
If you plan to use ammonia for a while, you will need to top up the levels, so to speak. The vapor won’t just hang around in the air forever; it’ll dissipate and might even make its way into your home. This is definitely the case if you are foolish enough to put the stuff next to a heating or air conditioning duct that would then freely send the toxic gases all around the building.
Using ammonia for bats is not smart. In the event that the bats aren’t forced to retreat somewhere deeper and darker, they will die. If they can’t escape the toxic space they have found themselves in, they will die. The adults might not be able to move their youngsters in the roost, meaning that all the baby bats will die. If you use ammonia in the spring or summer, you ARE without a doubt using ammonia on a maternity roost – mothers all flocked together to rear young. In almost all states across America, this is illegal.
Go back to the Bat Removal
page, or learn about bats in the attic with my Bats in the Attic
Reader emails about bats
I have read your guide for getting rid of the bats, and we have begun the process, however we have so many in 100 year old home, that I'm certain we haven't screened off all the areas, in particular the east side of our home. We are thinking of using ammonia to repel them, does that work? Our attic is a finished attic, used as a bedroom, but the smell from the bats up there is horrible. My question, being a 3 story home it is quite difficult for anyone to get up to that height to remove the siding, it is quite brittle also, due to the age of the home. The inside of the attic is finished in pine, beautiful. Do we have to take these walls off either in or out to remove the guano and urine, or will it eventually just go away. I'm also having a very difficult time finding someone to help us with the sanitation here in Medford, do you know where I can look for someone? I have had 2 different companies come out with their very high bids (insurance will only pay $2800 of it), but then do not hear back from them. Any help you can give us would be greatly appreciated.
Great website. I have always liked bats. The reason for my email, as if you don't know, I have some bats living in a hole where a piece of brick has moved by the roof overhang. I don't know if this hole leads into my attic. I'm also not sure how many there are. I can actually see one them sleeping right now at the opening. I live in New Jersey where the weather will get colder in the fall, so I have a few questions I'm hoping you can help me with: 1. You mention not to do anything until the pups can fly. Is that always around August? 2. The weather in New Jersey starts to get colder the middle of fall, will these bats actually leave my house and migrate somewhere? Or will they stay put and hibernate in that hole? 3. How will I know when they are all gone? Do I actually have to inspect the hole? Inspect my attic (yuck)? I want to make sure I'm don't hurt them. Will ammonia get rid of bats in the attic? Normally I would do nothing, but if their living space includes my attic, this is not acceptable after what I read on your website. Any information you could provide would be greatly appreciated. Hope to hear from your soon.
We don't have bats in the attic. We have them roosting under our portals and making a pissy, shitty mess of our house. I don't like to do it, but, I've taken to checking the portals just before going to bed and shooting any I see with pepper spray. That has reduced the problem, but is only temporary. will ammonia work to get rid of bats? We returned from a two week trip to find large amounts of bat poop all around. Any ideas? Netting all of the portals would be a very large job and would also be unsightly in itself. I've had some success* by spraying their favorite roosting spots with the same pepper and hot sauce solution I use to keep the rabbits from eating some of the plants in the yard. I do that just before I go to bed each night.