The best materials to exclude bats include foam caulking, screening, weather stripping, stainless steel, wood and flashing.

Foam caulking

Caulking is the process of sealing openings and crevices where bats take advantage and gain entry. Because building materials may contract and expand in different conditions, foam caulking is best applied during dry season for maximum effectiveness. Caulking may be applied using a caulking gun or pressurized containers containing expanding urethane.

Screening

An appropriate screening should have tiny meshes to prevent bat entry through them. The screening should be preferably made of ¼ inch steel. The screening type may depend on the Des Moines location where it is to be used or the type of ventilation on which it is applied.

Flashing

Flashing is installed at the point where the walls meet the chimney or roof. It contains strips of metal combined with other materials. Materials used include galvanized metal, steel and aluminum. A self-adhesive flash band may be used to ensure flexibility.

Weather stripping

These are special Iowa materials that are applied on the spacing between the bottom of the door and the floor. Weather stripping is made of Iowa materials such as fine wire, aluminum, felt, rubber and natural fiber. A sausage shaped, flexible tube made of cloth and sand can be used to seal holes at the base of the Iowa door.