Is this Mouse droppings?

Check your cabinet for any small cracks or holes the mouse could have slipped through. They can get through very tiny spaces. Also try Google searching "mouse droppings" and see if the images you find match what you found in the bag. If the bag was dirty or there are other things in the cabinet that could have left brown globs then that could be the cause. Also try to keep an ear out for any scratching sounds, and maybe ask your neighbors if they've suspected mice in their home. As a safeguard, it's never a bad idea to keep your pantry foods in plastic containers or other containers that are not easily accessed by pests such as mice or bugs.

I'm pretty sure that the color of mouse poop depends on their current diet, just as ours does. As for the stuff you found, it most likely is mouse poop. They can get in almost anywhere. If you're a clean freak, just throw that bag away and store them somewhere else from now on. If you're not, then brush them off into a trash container and go on with your life. Maybe put a small container of mouse poison in there if you don't have any kids.

Almost sounds like they were in the bag with your purchase . I hope it wasn`t food ???

It's WUMBO