A three-year-old child was among a trio of tiny vandals who smashed the windows and mirrors of an ambulance at Denmead.
The three children caused £500 damage to the decommissioned St John vehicle parked at Field Way.
But police were powerless to act because the children were all younger than ten – the age of criminal responsibility.
A Cowplain police spokesman said the three children responsible were aged three, six and seven.
The ambulance’s owner, Matthew Burnicle, aged 20, said he had planned to restore the vehicle and then offer it back to the St John.
He discovered the damage when he returned to his Field Way home.
He said: ‘I think what these children have done is disgusting.
‘What would their parents think if someone had come along and smashed up their family car?’