Our cat also brought one in a few months ago. Sat watching TV and heard this funny clicking, after a quick search found it under the table. I caught it in a shoe box while our lass looked on the web to find out what to do. It said to ring the local 'bat man'. He came around 2 days later, we kept it in a shoe box in the spare room. He went in for it but it had got out, finally found it, bit him twice. He left but haven't heard anything since. Never seen one flying around near us though.
Maybe linked, when we got our planning permission through for an extention the only condition was to stop work if we found bats. I searched all the related planning applications in the area and none mentioned bats.