  Assuming that dark matter (DM) efficiently clusters on various scales we
analyse the possible impact on direct DM searches. For certain sizes and
densities of DM clusters, mutual detector-cluster encounters may occur only
once a year or every several years leading to the apparent failure of
individual experiments searching for DM to discover it. If, however, encounters
with Earth size and up to $10^4$ times bigger clusters occur about once a year,
then finding time correlations between events in different underground
detectors can lead to DM discovery.
