I have often admonished parents that their children, even their very little children, are often much more attentive to what goes on at the altar then they are...
Case in point. . .
It is one thing to mock the things of God... it is quite another to find them a magnet and to desire, even from a young age and lacking much understanding, to appreciate what it going on at the Table of the Lord and to want to participate in these. Some may not like things such as this but I believe that where this proceeds from the piety of the child, under the good tutelage of parents who have brought their children often to the Lord's House, it is reflective of the young faith formed and nurtured by the Holy Spirit... And that is a good thing.
Parents, don't discount what your children learn from Mass... and don't park them in the back pews where they see nothing of what takes place... give them a solid view of the chancel!