  We present analytical results to guide numerical simulations with Wilson
fermions in higher representations of the colour group. The ratio of $\Lambda$
parameters, the additive renormalization of the fermion mass, and the
renormalization of fermion bilinears are computed in perturbation theory,
including cactus resummation. We recall the chiral Lagrangian for the different
patterns of symmetry breaking that can take place with fermions in higher
representations, and discuss the possibility of an Aoki phase as the fermion
mass is reduced at finite lattice spacing.
