cat laid an egg...

... this happened when we were 6 years old...
...in school, during recess three of us were standing by the window. Our classroom was on the ground floor, and the rear compound wall was a couple of metres behind the window. In between there was sand.
...while we were watching, a cat came by, dug a hole, did its job and went away after covering it up. Being kids, and not knowing the finer details of how animals multiply, one of us said... "cat laid an egg..." and the rest of us agreed.
a few days layer, the sand area was cemented and we felt bad that the "eggs" were lost. It was after 3-4 years later that we realized what the eggs were...