Follow the steps below!
I noticed that you have to connect a battery for each light bulb.
I noticed that for the 3 light bulbs you only had to use 2 batteries.
If the Christmas lights are arranged in a series circuit then when 1 bulb burst (is removed) the other bulbs light up.
i noticed that while i take i bulb out the others are still on.
i noticed that with out a batteries the lights do not light up.
A series circuit is the best series to use for Christmas lights because they name multiple more lights.