Staff at Rainbow Childcare, in Kilwinning, Ayrshire, were horrified when they arrived at work last month to discover the place littered with broken glass and tagged with graffiti.
Police were called in - and discovered that the culprits were primary school pupils aged just six, seven and ten years old.
The three children responsible for the damage, which was found on August 4, were said to have been 'dealt with'.
In May this year, a law was passed which raised the age of criminal responsibility in Scotland from eight years old, to 12 years old.
Kilwinning Locality Sergeant Allen Dodds said: "The youths who went out and damaged the nursery, there was a detection and that has been dealt with.
"There were three offenders, who were younger than just young people.
"These were pre-teens, three children of primary school age.
"In regards to youth disorder in the town centre, small fires have started getting raised again.
"I've devised a strategy now with North Ayrshire Council's anti-social behaviour team to target youth offenders and their families.
"There are things we can put in place to try and drive home a bit of parental responsibility of what their children are doing in the town centre and surrounding areas."
A spokesman for Police Scotland said: "We can confirm that enquiries into this incident are complete and we are not looking to identify anyone else."