No, not those sort of noises but rather the unmistakable sound of heavy porcelain being scrapped across the cistern.
It turns out that Archie was keen to discover what happened when he flushed the loo so was removing the lid each time. That's the thing with children, they are instinctively, constantly and, when you're reassembling a cistern five times a day, annoyingly curious.
Inspired by this, I decided to try some dual planting with the children at pre-school gardening club last week. I gave then each two runner bean seeds. One they planted in a pot of compost, the other was placed down the side of a clear beaker that was filled with damp kitchen roll or napkins. They were then able to taken them home, place them side by side on a sunny wondowsill and have an insight into what was going on beneath the soil. And after their curiosity was sated, they still had a bean plant which could be transplanted into the garden to grow, flower and fruit.
Now all I need is a see-through cistern.