The three R's

Today, I was lucky enough to be one of the judges to visit some of our local schools to see how they were developing their school grounds in relation to the Three R's, growing native plants, composting, encouraging wildlife etc
One pupil told me they were growing carrots between leeks and onions to discourage carrot fly.
He said, " I think it's called commensalism"
He was only about ten!!
Just to remind you, the three R's in this case are
REDUCE
RECYCLE
and
RE-USE
I really liked their use of old CDs
The extra shows where it has been placed