This thread is awesome. I will try to not spoil the awesomeness with my nerdy techno speak.
Cats are dedicated carnivores (obvs). So when they eat in the wild they will typically go for the most nutrient dense parts first. Brains, eyeballs, tongue, and the attendant glands in the head are VERY nutrient dense. Squirrel bones are also soft and easily chewed and digested. So there is rich calcium content in that skull, too. So the fact that your cat went straight for the head of a small rodent is no surprise. To your cat, that’s some good eating.
Had your cat been truly feral it would have saved the lower parts for later. But as a domestic it was expecting you to eat them.
Larger cats will go for the innards (liver, heart, kidneys, stomach contents) of larger prey first and then work on the head and muscular content (scraping hard bones for calcium).
One of my cats has severe food allergies and requires a raw food diet. So I switched them all to raw food. The results in health have been nothing short of amazing. But raw food is expensive when bought from the store. So I started making it myself. My research led me to all these little factoids.
Now once every six weeks or so I grind up 40 pounds of chicken meat, bones, liver, and eggs with added vitamins and minerals (B, E, Taurine, and iodized salt) and stock my freezer.
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