It is important to note that in many areas, bats are protected species. As such, these methods to get rid of them may be strictly specified and / or controlled. In these areas, killing or injuring bats may not be your best option
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However, probably out of desperation, or perhaps just imagination, there are reports of people using all sorts of poisons, chemicals, sprays, contaminants, etc, to get rid of bats. These include, various types of poisons, wasp and hornet spray, bleach, aerosol dog and cat repellent, aerosol “bombs,” ammonia, glue traps, mouse traps, rat traps, and more. The reasons for using these materials would include to out and out capture (glue traps) or kill (poisons) the bats, or to at least make their roosting areas so undesirable that the bats choose to leave the building.
There are reports of these poisons and chemical contaminants sometimes helping to get rid of bats. However, there are plenty of reports, as well, where these materials were not at all helpful in getting if bats. And, often just the use of these chemicals in the first place may not be at all desirable.
For example, using poison may very well not be a good method for getting rid of your bats. A bat could ingest enough poison to get sick, but not to die. In this case, the bat might just suffer, and still not move out of your house. Or the sickened, partially poisoned bat may be eaten by another carnivorous predator, like a fox, and inadvertently sicken the fox. If the bat DOES ingest enough poison to die, it will likely first crawl into a very small, inaccessible space in your house, and then die.
If you are unable to immediately find the dead bat, it will decompose, resulting in a terrible smell, and creating the environment for the growth and spread of additional bacteria and viruses. Ultimately the growth and spread of bacteria and viruses is exactly what you are trying to prevent, rather than to inadvertently cause in the process of getting rid of your bats.
Some of the same potential problems as above exist with using other forms of “killing” traps, like mouse traps, rat traps, glue traps, etc. The bats are likely considered to be “protected” in your area, and you will want to avoid dead, decomposing tissue in your building.
Clearly, poisons, chemicals, traps and the like are not the best methods for getting rid of your bats. There are other much more simple, effective, and humane methods available, and are described on this web site.