It's a mystery

Today I was cleaning the bedrooms upstairs when I heard the kids rummaging through the refrigerator. As I was coming down to check it out, I heard Rosie say 'Hurry clean it up, I hear mom". I come down and there is about 2 pounds of shredded mozzarella cheese on the floor. Rosie ran to try to stop me before I got into the kitchen while Matty is feverishly trying to put the cheese back int he bag. I asked Rosie what happened, she said, "There is a mysterious mess on the floor".