bat smell in attic


I had a bat problem for which I did an exclusion. They have not been back since. I cleaned the attic and sprayed a bleach mixture at the time. All seemed ok but at certain times I still get a smell. I was hopeful that it would just stop by it’s self but that doesn’t seem to be the case. It only seems to happen when the weather is humid. Any thing I can do to get this smell out once and for all? Thanks.

Absolutely. If you review the products listed in our BAT CONTROL article, you’ll see we have several designed for cleaning up bat droppings and the odors associated with their presence. As you’ve already learned, bleach will not get rid of the smell. In fact bleach will take away the color of many things but it’s not designed to kill anything and since odors are very much “alive”, you’ll need to use special agents to render them useless and non offensive. Odors will live for many years and in most cases, just go dormant when it gets dry and/or cool. But once the local air temperature reaches a certain level along with the right humidity, you’ll no doubt notice the smell come back.

Now the best product for killing the smell is NNZ. This material can be applied to the attic by either spraying or misting. Mix 8 oz per gallon of water and use the mixture over 500 sq/ft of surface area. Expect to get immediately results; within a day you should notice a significant drop in the odor. In general, 1-2 applications will solve any problem but you’ll need to give it 3-4 days per treatment to let the active do its job before you know if you need to treat again.





Apply the mixture with a good PUMP SPRAYER if the is no concern about the liquid leaking down through ceilings and causing cosmetic issues.





Remember to treat the insulation thoroughly since it will be harboring the odor. And if you can’t accomplish this goal with the sprayer, rent a BG2300 MISTER. This will allow you to get the entire attic treated without having to navigate around the attic space much since the mist will permeate well and carry the NNZ to key areas. Rentals cost $50.00 but we pay the shipping to you and back so its more like $25.00-30.00. But since these machines will do the job so much faster (and in most cases better) compared to spraying, its well worth the cost.





You can also purchase a fogger if you think you will need it for an extended length of time. These machines are great to use in and around the home for all kinds of pest control too so its not a bad investment. For any attic, our MINI FOGGER will do a great job. It only has a quart holding tank so you’ll be mixing just 2 oz per 32 oz of water instead of the 8 oz per gallon when using the pump sprayer or the larger fogger. And the 32 oz should be used over 125 sq/ft – not 500.





As a last resort, you may have to remove all the old insulation, treat the exposed wood and then re-insulate. I’ve seen where bat droppings can accumulate so much that the old insulation is not “savable” and since you didn’t mention just how bad the bat problem was you had, I cannot say for certain if this will be required or not.


Comments on bat smell in attic Leave a Comment

August 29, 2012

Tom @ 11:33 am #

My attic is pretty big with small access to the eves where I think the smell is coming from. Since I can’t get to the eves I think I’ll need to use the fogger. The bat infestation I had was pretty bad. Will using NNZ remove the odor permanently or does it just work for a while and then the smell comes back?

August 31, 2012

Tom @ 3:32 pm #

How do I determine how much NNZ product I’ll need with the BG2300 fogger? I figuring I’ll treat twice either way. I want to make sure I get this resolved once and for all. Thanks again.

November 22, 2015

Betty L McDonald @ 7:56 am #

We have a 4500sf barn that had a lot of bats (less and less each year) that we want to discourage in the Spring, since we are opening for barn weddings. We are having it cleaned by vacuuming the guano off rafters, beams and floors. Can we then use the foggers with the NNZ to eliminate the pheromones? Thanks, Betty

November 28, 2016

Wm @ 3:08 pm #

Thank you for posting these helpful Q & A’s. My question is related to the effectiveness of the NNz in relation to the temperature. I have an unheated 2nd floor with attic which is where the bats lived for several years.

I’m thinking the chemical is more effective at higher temps. Is this correct? This is one of my winter projects, but if I need to wait until summer to treat for better effects, I will. Thank you.

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