  The Cosmic Neutrino Background is a prediction of the standard cosmological
model, but it has been never observed directly. Experiments with the aim of
detecting relic CNB neutrinos are under development. For such experiments, the
expected event rate depends on the local number density of relic neutrinos.
Since massive neutrinos can be attracted by the gravitational potential of our
galaxy and cluster locally, a local overdensity of relic neutrinos should exist
at Earth. We report the status of our knowledge on the clustering of neutrinos
and the consequences for future direct detection experiments.
