Attic Cleaning & Restoration Services
If you find piles of mouse like fecal material in your attic or on the ground outside your house, then you probably have bats. (Bats defecate before they enter your home and below where they roost for the day)
Make sure that the fecal material is not old by laying down a piece of newspaper and see if any more droppings fall on the paper over the course of the next night. If there is, you have bats.
Just a word of caution about bat droppings: They can carry a fungus called "Histoplasma Papsulatum" known to cause Histoplasmosis.