Here is a list of things you will need...
Cardboard roll from paper towels or toliet paper (depending on how large you want your bat)
Burned out light bulb
Masking or duct tape
2 pieces of cardboard (to cut wings from)
Paint (regular or flourscent)
Hot glue gun or super glue
First take the 2 pieces of cardboard and draw a wing on each one then cut them out and set aside.
Then take the burned out light blub and insert it into one end of the cardboard roll and tape where they come together. (be carefull not to press to hard you don't want to break the light bulb)
Cut off two triangle corners from left over cardboard from wings, take one end and roll up to make a cone, hot glue or super glue the edges of the cone together then glue the cones carefully to the light bulb (these are your ears)
Then tape or glue the wings to the side of the cardboard roll really good.
Now you are ready to paper mache' it with a glue mixture and newspaper strips.
After a few days when it has dried completely you can paint it and coat it with an acrylic clear coat or polyurathene to weather protect it.
To hang it hot glue fishing line to the top of the bat- then hang!!