Many many years ago I took my son Stephen (then aged about 2, now 25) to the beach with some other mums and small kids.....Stephen was happily playing in the sand, I was stretched out in the sun feeling lazy when someone else's small boy near me started to dig in the sand and I was getting sprayed. I was too lazy to move so I asked him to go somewhere else. He said in a tone of great urgency "but I gotta dig!" I said to him "it's an inner compulsion is it" and he said very seriously "no it's a hole!"
All those years ago, and I have never forgotten - but it did teach me that sarcasm is wasted on small kids.
Cheers
JennieG