yeah you gotta glue the hat down (and I too glue the candy bar on to the wrapper a bit) otherwise the hats will fall off and then you have to KEEP PUTTING THEM ON DURING THE SALE. Which apparently can be quite frustrating for some!!!
Last year, when I did the snowmen, I apparently glued things down so well that you had a very hard time opening them up to eat the candy. I think I used the red line tape but they were very sealed! Oh well.