Bats are harmless flying mammals that are nocturnal. They like to roost in quiet, dark enclosed areas like wooden bridges, barns, dead trees and attics. You can make an indoor area less habitable for bats by applying harmless aromatic scents like oils of spearmint and peppermint.
Things You'll Need
- Spearmint oil
- Absorbent material
- Small ventilated container
Get the spearmint oil. Spearmint oil is extracted from the spearmint plant. It is pleasant-smelling and usually comes in a "vehicle" like mineral oil, propylene glycol or alcohols. The strength of the oil is listed by percent. You only need about 2 percent strength to deter bats.
Use an absorbent material. Spearmint oil is not water soluble. You can apply it directly to wood or painted areas near where bats are roosting, but it is more difficult to remove and may cause discoloration or stains. Use an oil-absorbent material to hold the scent. A common oil absorbent material is known as "fuller's earth." This is a type of clay used to absorb grease and oils. It is available as powder or solid and will make the scent last longer. For shorter-term use, cotton gauze or cotton balls will work.
Combine the spearmint oil and absorbent material. Knead the oil into the absorbent material. Spearmint oil (depending on the solvent) is edible and not toxic. You don't want to get it in your eyes. Use about 10 to 20 drops of oil per cotton ball or similar amount of fuller's earth.
Place the material in a container. A small plastic container like a discarded pill bottle will contain the oil so it doesn't leak or stain the surroundings. The container has to be open and breathable to allow the oil to permeate the air.
Put the container in the roosting area. Choose a spot that has poor circulation--the scent will permeate away from this area throughout the roosting area. Use about one container for every 100 to 200 square feet of space. Place multiple containers in different places to cover more area.
Add more containers. If you still have a problem, try adding more containers or using more oil in each container. You can add more oil to the original absorbent material about once a week to once a month depending on whether the scent is weakened or if you still have a bat problem.