“All of my baby cabbage plants were gone this morning.”
You tell me you keep the squirrels cleared out, so what could eat those plants? Possums? Have you ever seen any there? Raccoons? Have you ever seen any there?
I'm thinking more along the lines of an insect of some kind. They were tiny little plants. There were no paw-prints in the soil, and I look for those, because there won't ever be any 4-footed critters in my yard. Not for long anyway.
/johnny