Three boys under the age of 10 have trashed a house, causing tens of thousands of dollars damage in Geraldton in Western Australia.

Marianne Miller arrived at her investment property in Rangeway Tuesday afternoon to find windows smashed, carpet ripped up, paint strewn around the house and an air conditioning unit torn off the wall.

Interior and exterior walls had huge holes kicked in them and some were ripped down completely.

Two boys, aged eight, and another aged nine have admitted to police their involvement in the vandalism.

Due to their ages, the trio is exempt from prosecution but have been referred to child protection authorities.

Ms Miller said she rents the house out and was in between tenants when the vandalism occurred.

She was speechless after seeing the damage and could not fathom the children's motivation.

"I was just completely in shock," she said.

"I didn't know what to do, I was just shocked, speechless. The amount of damage that they did - for children, they must have spent quite a bit of time in the house over the weekend.

"I wouldn't have a clue why kids would go and do something like this to my house. The only thing I can think of is they're bored.

"They're babies, they need to be guided in the right direction.

"Where are the parents? What are the parents doing at the time when [they] are completely ruining a house?

"I am actually amazed kids could do that much damage. I couldn't imagine my kids who are the same age being capable of doing that much damage."

Trio exempt from prosecution

Sergeant Shilo O'Neill said it was uncommon to see such extensive damage caused by young children.

She said two of the boys were from Geraldton, while another was from the Perth suburb of Nollamara.

The damage to the house was significant. ( ABC News )

"Their parents were obviously made aware of the situation because they were present during our interview," she said.

"What we do now is put in a referral to Child Protection and Family Services who will now make contact with that family and deal with them.

"The damage is certainly quite significant and it's not very common for this sort of thing to occur.

"We have on the occasion from time to time had similar incidents of this nature, but it's not something that is prevalent in the community."

Ms Miller said a new tenant was scheduled to move into the house a day after the damage was done.

She said she had begun the process of making an insurance claim.

"They've absolutely destroyed the property, they've knocked all the walls in, the walls are actually exposed to the outside of the property," she said.

"Before we boarded it up, you could literally walk into the room from the backyard.

"There's paint all over the kitchen cabinet, basically every room has been touched.

"In the bathroom, the wall has been kicked in, the doors have been ripped off and there's paint all over the bath.

"Today a quote was done by a building company so we're waiting to hear back from them on what they estimate the cost to be.

"I don't think it will be pretty; it will be up there."