Eggshells make a great science project because they may seem delicate, but they actually possess surprising strength. They are designed to protect the developing embryo inside the egg, so they have some resilience. The strength of eggshells can vary depending on factors like their thickness, the type of animal they come from, and the conditions in which they were formed. While eggshells aren't as strong as materials like metal or wood, they can withstand a certain amount of force before breaking or cracking. It's important to handle them with care, as they are still fragile. If you're interested in learning more about the mechanical properties of eggshells, you can check out this article from the Exploratorium, a reputable science museum: "The Incredible Eggshell."