Object Permanence---Michael and the Cats

Since Michael learned to crawl proficiently, his constant goal is the cat food outside the bathroom. I've hauled him away from it dozens of times. I decided to try another strategy. I covered the food and water with two box covers. Nate couldn't figure out where they had gone and turned around and chased the cat. The cats knew very well it must be there, but could not figure out how to take off the covers. Michael could have gotten them off immediately if he realized what they concealed. I am grateful Michael and the cats don't collaborate.