The best way to get them out without hurting them is to put a panful of ammonia into the fireplace. Close the fireplace doors and open the flue. The smell of the ammonia goes up the chimney and after a short while the animals clear out. When you are sure that there are no more animals up there, put on a chimney cap. Don t chase it around and don t try and pick it up yourself.
Some animals carry disease and can bite through gloves.
If you give it room it will probably leave the way it came in. The best thing to do is open a window. Then close off the room from the rest of the house. Turning out the lights helps. With the lights on, a bat seeks a dark place which is usually your furniture or curtains.