Bats sleep during the day, hanging upside down from the roof rafters or on an outside wall. Contrary to popular ideas, they do not like belfries as they like draft free locations.
Various types are native to Ireland and are usually seen around dusk as they sweep across the sky catching air borne insects. They cause no harm and under Irish law, can only be handled by licensed people.
Remedy:
Law protects all species of bat found in Ireland as they are endangered species, it is illegal to kill or even disturb bats in their roosts.