Victor Grange member Barbara Bailey speaks about the infestation of bats inside the Fairfield building on Monday.

A recording device from the state Inland Fisheries and Wildlife department will record the comings and goings of bats in the attic of the Victor Grange in Fairfield this year. Once the bats leave next fall, the holes they are using to enter the building will be plugged up.

The Victor Grange in Fairfield is the summer home of a colony of bats, and the guano from decades of them living there is causing damage to the building.

A little brown bat with white nose syndrome. The bats are an endagered species because their population has been decimated by the disease, but colonies may still be spending summers in the attic of the Victor Grange in Fairfield.

Victor Grange member Barbara Bailey, standing on a ladder in Fairfield, surveys the floor of the building attic, which is covered with bat guano. The decades of guano is eroding the building.