Checked common hitchhikers and looked around and couldn’t find these tiny little guys with a chiton-like shell (meaning it might be articulated and is only on the back of the animal)
A foot not feet - so ok, I was leaning toward chiton but hadn’t noticed them before today - I thought it was ok but since they seemed new I got nervous. I definitely also have limpets. I had like two big ones and now I have approximately 1 gazillion baby limpets if anyone wants some….