Centralia police say a witness spotted the two vandalizing the building. The witness then followed the girls to a local home and called 911.
An officer responded and the witness pointed out the home where the girls had gone.
The officer was able to look through the window and see the costumes, which looked like peeled bananas, lying on the floor of the house.
The girls were arrested for investigation of third-class malicious mischief and then released to their parents.