This past weekend my mother asked the age-old rhetorical question about why cat food manufacturers make various flavors of cat food, but don't make rodent flavor, since cats are known to enjoy rodents.
Well, I actually might have an answer...
Cats get get rodents fresh (and possibly more frequently than us humans actually know about). But most cats, especially house cats, can't easily get fresh chickens, fresh beef or fresh fish (besides, most cats don't like jumping into the water for fresh fish anyway, it messes up their coats).
It's like people... How many people who might have delicious tomatoes growing in their garden are going to go to the store to buy packages of tomatoes?
Same with cats. When they can get fresh, juicy, tender, bloody rodents to chase, frighten, tease, kill and eat, why should they settled for processed and packaged rodent meat?