At cold temperatures, many body quantum systems show interesting features not known from classical gases. One famous example is Bose–Einstein condensation, where the correlation between the Bosons leads to an aggregation of Bosons such that there is a macroscopic occupation of the same state. For Fermions one encounters a contrary effect: The correlation between the particles that comes from the anti-systematization works against aggregation. Fluctuations in the gas are heavily suppressed, dissipation and friction of particles entering the gas are heavily reduced. In the talk I will present recent findings on the dynamics of an additional particle — called impurity — interacting with the Fermi gas. The results show that, in fact, the impurity moves freely on a time scale much longer compared to the time scale one gets for a classical gas or a Bose gas. Many such impurities will be subject to an attractive interaction mediated by the interactions with the gas.