A childhood belief about general

You remember all those old cartoons where cats would get chased by dogs? This is how it worked in my mind: Cats ate mice, birds, or fish. Mice only ate cheese. Birds ate birdseed. Fish ate eachother. ...And dogs ate cats and bones.
I also had no idea the bones that dogs ate were actually once part of an animal. I knew about people & animals having bones & all that, but it just never occurred to me that it was once part of a living thing.
Furthermore, i thought that when animals got eaten by other animals, they'd just set up camp in the belly that was now their home & eventually escape.