They are Hibernating for the winter sas and when the weather warms up they will fly out the Window themselves. They eat Garden pests so are useful for any Garden.
I have hundred (literally) in an loft window - they do no harm and as previously stated are such a boon in the garden. Let them over winter with you and be glad they have chosen your house - as the weather warms up (if ever!) they will become more active and can be let outside.