So here is what I found at the grocery store after Easter for $.50. K loved them. I have never seen them up north but I'm sure creative people could easily make them for a fun art activity. Or, you could probably use plastic eggs.
My child loves to help crack eggs in the kitchen, messy, but these were fun and a little messy.
First she painted glue on paper (my suggestion) and then just poured the glue on (her suggestion). Her suggestion looked better on the end product.
She kept cracking even though I suggested saving some for later. But, there was a lot of confetti I collected to use later.