@kalma The thing about bug zappers is they attract bugs before they kill them. You do not want this anywhere near you. If you want to use a bug zapper place it 100 to 120 feet away from where people will be.
@butkus Re Battery: Twist off top cover, then twist off the interior cap to expose battery compartment. If battery is inserted, you will need to remove the protective covering. If not already inside, place the included battery into the comportment and replace the lid. (Tip: the battery is not marked so if it does not work simply flip the battery over)