  We address the locality problem arising in simulations, which take the square
root of the staggered fermion determinant as a Boltzmann weight to reduce the
number of dynamical quark tastes from four to two. We study analytically and
numerically the square root of the staggered fermion operator as a candidate to
define a two taste theory from first principles. Although it has the correct
weight, this operator is non-local in the continuum limit. Our work serves as a
warning that fundamental properties of field theories might be violated when
employing blindly the square root trick. The question, whether a local operator
reproducing the square root of the staggered fermion determinant exists, is
left open.
