After you cook some eggs, don't throw out the eggshells. Save them for anti-pest control in your garden.
Photo by Phú Thịnh Co
In an article about using kitchen waste to improve your garden, Popular Mechanic advises:
Crush eggshells into small pieces and sprinkle them on top of the soil. Slugs, cutworms, and other insects are put off by the crunch when they crawl over the sharp edges and will leave for softer pastures. You can also toss the crushed shells into your compost heap. They break down quickly and give your plants a much-needed dose of calcium, which can help with bottom-end rot, a calcium deficiency found in some plants.
Smart use of an item that would normally end up in the rubbish.
Banana Peels, Eggshells, and More Trash Your Garden Will Love [Popular Mechanics]