10 Smart Ways to Use Leftover Eggshells Around the House

It might seem counterintuitive to take something that you might normally toss in the trash, and put it into your morning coffee. But because the calcium carbonate in the shells absorbs acidity, this trick actually works to make a better cup of joe — at least, if you're using beans that taste a little too bitter or acidic for you. In that case, crumble a bit of clean shell and add it to your coffee grounds before adding water. This works best in a drip coffee maker, since it keeps shell from actually getting into the water.

The nutrients in eggshells can ultimately help your garden grow. Keep shells to toss into compost, where they'll eventually break down and add calcium and other minerals to the mix. Let shells dry out on a counter for a few days first. Then break them into small pieces before adding them to compost, to help them break down as quickly as possible.

It takes a lot of creativity to keep kids entertained. Save eggshells to transform into colorful crafts on a rainy day. Pieces of broken shell can be glued to paper to make mosaic designs. Help kids paint or dye pieces of broken shell, or leave them plain and create white mosaics on colored paper.

Calcium builds strong bones and strong plants, too. If you don't have a compost pile, you can add eggshells directly to the soil in your garden. Large pieces will take a long time to break down, so let shells dry and crush them into small pieces first. Sprinkle at the base of your plants or mix the shells directly into soil.

Sometimes, you've just got to put the bills aside and go play hopscotch with the kids. Instead of spending cash on colored chalk, make your own at home. All you need for homemade chalk is eggshells, flour, water and food coloring. You can even use molds to make chalk in shapes that kids will love.

Eggshells are for the birds.... literally. Their calcium content makes them a safe snack for your feathered friends, and adding shells to your birdseed might actually attract birds to it. Let clean shells completely dry out on a counter for a few days, or bake them at low temperatures until they're brittle. Crumble and add to your bird feeder.

If you don't have a bottle brush on hand, cleaning the inside of a tall vase or thin-necked water bottle can be a real challenge. Use the abrasiveness of eggshells to solve this problem. Drop crushed shell into these hard-to-clean containers, along with water and dish soap. Swirl the mixture vigorously to help the shells remove any stains, then pour everything out and rinse with plain water.

A baby plant is a delicate thing. Seedlings don't need a ton of space to grow in at first, so halved shells make the perfect first home for new plants. Nestle shells in a bed of soil to keep them stable, then fill each one with soil and one seed. When the plants start to grow, transferring them to larger pots is as easy as breaking up the shell.