do not stick two copper wires on a nine volt battery then connect the ends. but if you do not heed this warning and walk around the house telling people to touch the bare wires well, make sure you fingers are not completely on the battery thingummies it gets hot. and the people touching it get a rather shocking experiance. oh, and one more thing, don't stick your tongue to it ether especially if you have braces on. if you want a sample of a battery shock just go lick a watch battery for a little while. or bit tinfoil.