An interesting tidbit about cat behavior: in this BBC clip from Cats Uncovered, veterinarian Dr. John Bradshaw of Bristol University says that cats use the vocalizations that work on their mothers when they're kittens (and then stop working when the kitten is weaned) with their humans as a way of getting attention:
The meow starts off as a kitten vocalization. Its something they use in order to call their mothers over…the mother is very attentive to those meows. And then as the kitten grows up, it gradually stops meowing, presumably because it just stops working. The mother wants to wean the kittens and stops responding. A pet cat is constantly meowing at its owner. It’s a way of getting the owner’s attention.
via Laughing Squid.