I will briefly describe the formation and properties of Gamma-Ray Burst (GRBs) and outline their role as tracers of the cosmic star formation rate, before turning to the host galaxies of the bursts. The observed properties of the hosts show them often to be of rather low metallicity and/or of a rather high specific star formation rate. It has been debated which of these properties is a dominant factor in determining if a galaxy will host a GRB or not. In fact, there are indications, at least in the local universe, that the two may be anti-correlated and that the metallicity is the deciding parameter. I will compare models of both quantities and show that when compared with best available data, the fraction of GRB-hosting galaxies as determined by the specific star formation rate, follows more closely the observed production fraction of bursts.