  I discuss minimally doubled fermions fermions as an ultra-local formulation
on the lattice for sea quarks that realize a non-singlet chiral symmetry. I
introduce a non-singlet mass term for Karsten-Wilczek fermions and identify the
appropriate representation of the SU(2) flavor group at finite lattice spacing.
I present an algebraic proof that the symmetry of the quark determinant under
charge conjugation and reflections of the Euclidean axes is preserved for
Karsten-Wilczek fermions as sea quarks. Finally, I discuss how the flavor
components in meson correlation functions with Karsten-Wilczek fermions emerge
naturally and I show how taste-breaking can be avoided without fine tuning.
