Is it possible or do they think so literally that there is no point? I was trying to explain to my DS (3) yesterday that there was nothing inside his bouncy ball. He kept protesting that there was so in the end I told him there was only bounce in there and nothing he could touch. Of course, 20 minutes later, he's bitten a big hole in the side of it in an attempt 'to get the bounce out'.
Is there a better way to explain things? Should I have said that the ball was made of rubber and that rubber bounces? Just idly wondering really ...