The other day I remembered a fun little activity my mom helped me with as a kid, and we decided to try it out: making rainbow crayons.
*an aluminum baking pan, any size
Have the kids gather all the little broken bits of crayons from their stash. (You may not want to use too many dark, "blah" colors (like brown), because they tend to overpower the end result.) Then, have them peel the wrappers off and place the broken bits in an aluminum pan. We happened to have a fun little mini-loaf size on hand, but if you have enough crayons even a brownie pan size will do. Meanwhile, preheat your oven to, oh, I don't know...hot. Let's say between 250-350 degrees.
Once the pan bottom is mostly covered with crayon bits, place it in a hot oven until it all liquefies, about 5 minutes. (You will know when it's liquid because if your kids are like mine, they will plaster themselves to the oven window staring in the whole time.) Note: you may notice a funny smell while melting occurs. If it's not coming from your baby's diaper, it's probably just the crayons.
Once liquid, remove the pan from the oven and place it on a flat surface in your refrigerator, on top of a hot pad. (What? You don't have a flat surface in there? Me neither, but you'll have to use this as a motivation to clean out your fridge while the crayons are melting. Yes, I know that takes more than 5 minutes, but at least clear a little spot.)
Allow the melted crayons to firm back up and cool completely. This takes about 30 minutes. Gently pop the rainbow chunk crayon out of the pan, and after admiring and caressing its smooth underbelly, break it into pieces. If it's thin enough, the kids may enjoy breaking it themselves.
Voila! A fun, free little craft, something to keep them occupied for quite some time, and a perfect way to rid yourself of all those annoying little pieces of crayon that are otherwise useless. And if you're Type A like me and don't usually allow your kids to peel their color wrappers off, they'll be so excited that you're actually asking them to!