Go Away, Big Green Monster!

At the beginning of the school year, we read Go Away, Big Green Monster! The kids LOVED it, so we made little brown paper bag puppets of the Green Monster! At the time, we were just starting to read, se we used our puppets to help us read. We also read in "monster" voices, which the kids loved! As a reminder, I made a monster face bulletin board, taped all of their puppets to it, and hung it on the ceiling. At first the kids were a little scared of it, especially when it fell down on one of the students! She wasn't too happy, but we all ended up laughing. Now, I can't figure out how to keep it up on the ceiling. I'm guessing there is a bit of moisture in my room which makes things fall off my cinder block walls all the time!