Buy 1/4-inch thick netting from a local hardware store. Watch your house at night when the bats leave their roost. See where they leave from. Investigate from the inside and find the hole or holes they are leaving from.
Cut the netting into strips so that it will cover the holes the bats exit your house from, leaving a foot of netting to dangle below each hole.
Fasten the netting tightly over the hole from the outside with the thumb tacks. Leave the bottom part of the netting open and hanging down. The purpose of this is to let the bats fly out of the hole from the bottom where it is open, but they will not be able to get back inside when their hunting is over for the night.
After a few days, when you are sure all the bats are gone, you can fill the holes with plaster. The bats don't chew, so they will not be able to get back inside.
Things You Will Need
- Thumb tacks
- You can provide the bats with a bat house in your yard if you want to keep them around and offer them a new place to live once you have excluded them.