None of the first few pages were of much use, so I restricted my search by adding a requirement that it contained the word "cat":
Hmm. So those + signs there are supposed to mean "must contain". If I ask for pages that must contain "kibble" I get 2,450,000 results; if I ask for pages that must contain both "kibble" and "cat", I get 3,010,000. That means there are more pages that contain both words than there are pages that contain the first of them with or without the second.
How does that work then?