  Worldline representations were established as a powerful tool for studying
bosonic lattice field theories at finite density. For fermions, however, the
worldlines still may carry signs that originate from the Dirac algebra and from
the Grassmann nature of the fermion fields. We show that a density of states
approach can be set up to deal with this remaining sign problem, where finite
density is implemented in a canonical approach by working with a fixed winding
number of the fermion worldlines. We discuss the approach in detail and show
first results of a numerical implementation in 2 dimensions.
