First of all, lock all your pets in their cages or in a room while getting rid of the bat in your house. The war between you and the rat might just frighten them.
Put on your safety gloves (prevents from rabies) and get hold of a container (a shoebox perhaps) to trap the bat in.
Take a worn out towel that you can dispense with. Wait for the bat to settle down. It can choose a wall or ceiling. When it does, throw the towel over it so that it cannot escape.
Grab the bat and put it into the box. Cover it with a lid or towel.
Release the bat outside your house.
Throw away the box and towel and wash your hands with an antiseptic.
Hug your pets. You just got rid of an intruder!