  Sterile neutrinos coupling only to third-generation fermions are attractive
dark matter candidates. In an EFT approach we demonstrate that they can
generate the observed relic density without violating constraints from direct
and indirect detection. Such an EFT represents a gauged third-generation $B-L$
model, as well as third-generation scalar or vector leptoquarks. LHC
measurements naturally distinguish the different underlying models.
