Clay Seals Project
The people of Lerna, from the Early Bronze Age in Greece, about 2100 BC, had many baskets which had been sealed with a special mark pressed into a lump of clay. This shows that people cared about protecting their property so it would not be stolen.
You can also make seals and seal things. Seals can be made from anything hard enough to mark wet clay (or Play-Dough). You might try carving wood, or making seals out of clay and letting them dry. Be sure to design a seal which is different from anybody else's!
Take a box, like a shoebox, and put something in it. Put the lid on. Stick a gob of clay over the join between the lid and the box, to stick the lid closed, and press your seal into it while the clay is still wet, then let it dry.
Or, just put a small object inside a gob of clay, then seal it and let it dry.
Now mix yours up with other people's. Can you tell which belongs to whom, by comparing the seals? What if you were a thief? How would you try to steal this stuff? What problems would you have?