Interesting! Thanks everyone!
She was born in a barn and has probably had to fight for her food her whole life so that's probably it. She even growled at her kittens (they were a couple days old
) while she ate when I first got her. It makes complete sense that she's just trying to save it for later.
While it is a little disturbing in the night, I'll forgive her
as I'm just happy she's safe and sound and getting healthy.