They're really easy to make and look pretty good hanging from a branch. Last year it was too late to make a tutorial so I'm doing it now.
Here's what you need:
paper pattern (Make your own by drawing a similar shape about 15cm across and 5cm high. That size they hang the nicest, the wings are just light enough to not droop.)
Black felt
Bits of toy stuffing (or some bits of cut-off felt)
Black thread
Scissors
Sewing needle
Pins
Cut out two felt bats by placing your paper pattern on a double layer of felt, pinning it into place and cutting around it.
Pin the two felt shapes wrong sides together and sew them together with a simple running stitch around the body first, kind of cutting off the wings:
Leave a little gap in the seam and push some toy stuffing into the body before stitching it closed.
Then stitch a line of running stitch around the edges of each wing. And that's it! Attach a long piece of thread from the back of the head and hang on some branches or the ceiling.