As a fun little lesson for all those hard boiled eggs that come about from celebrations of Ostara, or Easter in a few weeks, is Earthquakes. This blog link here gives a lot of detail about the concept. But basically broken down the egg is the earth. Smash the egg so the shell is broken up on the outside a bit and you have a representation of the plates for the earths crust. The larger cracks are the divisions and the smaller ones are the more minute cracks within those plates. Letting the kids play around with how pushing on one "plate" will allow them to experience how the earths crust moves about and the effect that earthquakes have.
Another fun little tip, the ideal fail proof way I found of cooking eggs for easy peeling is to steam them. Start a pot of water and place a steam basket over the top of it. When it starts boiling, take the eggs cold from the refrigerator and add them to the basket. Cook for 11 minutes, and remove to an ice bath This will create easy peel eggs.
Have fun with this great little experiment! Happy Ostara!