Q: Yes, that is right. We have BATS hanging on the wire screen behind the Air Louvers. Is there anything that I can spray on them from inside the attic to discourage them from returning.
A: If you spray water on them on a warm day like today (so they don’t get chilled) they will vacate the louvers temporarily, but they will probably return.
Before they get back, staple a piece of sheet plastic above and on both sides on the outside of each louver opening, leaving two feet of the sheeting to hang loosely below. When bats return, they will hit the plastic and slide off. With the attic no longer available, they will fly away in search of a new abode. Once winter arrives you can remove the plastic.
The likelihood of them returning next year is not big.