Firstly, the clergy. It may be very distracting for the priest, when, halfway through the Eucharistic Prayer, a child starts to make a loud noise. Some older priests in particular might find this makes the saying of the prayer more or less impossible. This may be particularly so in some modern churches that have a terrible acoustic that magnifies every noise, particularly those that are high pitched.
One feels for such clergy, at least some of the time, but what they must do is really simple: grin, bear it, and carry on. They must raise mind and heart to God, and pray the Mass as if they were in the most silent of convent chapels. After all, back in the day, many priests celebrated Mass on battlefields with shells bursting around them. They too carried on and did not complain.
If the priest stops the Mass and demands the child be removed – and this does sometimes happen, though rarely, it has to be said – this will effectively hold the parents up to public blame, and ensure that they never come back to church. Besides which, the parents do not need to be told – they already know that the child’s behaviour is not good, and are already, probably, doing their best to keep the child quiet.
What should parents do? They are the second group to be challenged by the child. They are probably doing all they can already – after all, they live with their child full time. They are the experts in child management.
They could take the child out, if this can be done quietly and unobtrusively; though sometimes this creates more fuss than it saves. They may feel very embarrassed by their child’s behaviour, and the priest should make it clear to them, I think, that he really doesn’t mind. After all, a very quiet church would also be a dead church, if it were child-free.
This brings us on to the third set of people: The rest of the congregation.