this is something I used to do in elementary school. Around when I was maybe 9 or ten years old.
I don't know why I remembered, but one night I was bored and decided to do this with my little sister, so it came out handy :)
gather your supplies
the long strips of paper, you can easily just cut a long stroke off an A4 stencil.
and you can probably get your hands on some cheap book.
if you would want to decorate the book itself, you can do so. maybe with some paint and colored pencils or just more coloured paper
the first thing you want to do is glue all pages together to the back of the book.
DON'T GLUE THE WHOLE PAGE! JUST THE SIDES
so just start with the last page, glue it to the cover and work your way to the first page.
you can leave a few first pager unglued if you'd want to
so now you're going to make your little bookworm.
take your 2 strips of paper and glue them together the way it's done in the picture
fold the bottom-strand over the top-strand and continue doing this.
(so what we did was fold the blue over the pink and than pink over blue, blue over pink etc.)
don't forget to glue the ends together
it's pretty easy, I let my 5-years old sister do this part
then you're going to cut out a little circle for the face, then draw a face on it and glue to your folded strand of paper
my little sister did this as well :P
when you're done with that, draw a cross on the top page.
you can make it as small or big as you want, just make sure your worm fits in it.
then cut along the lines, so you can rip out some sort of circle, so it looks like the worm has been eating through the book
glue the worm to the book and push it down, close the book
so when you open it, it pops up
finally, finished! :D