Superluminous supernovae (SLSNe) were only discovered recently due to their strong preference for faint dwarf galaxies. Understanding why stellar evolution yields different types of stellar explosions in these environments is fundamental to both uncover the elusive progenitors of SLSNe and to study star formation in dwarf galaxies. In this talk, we present our findings of the ongoing SUperluminous Supernova Host galaxIES (SUSHIES) survey. We present photometric properties of 53 hydrogen-poor and 16 H-rich SLSN host galaxies out to z~4. The size of the sample and the probed redshift interval allow us to constrain the redshift evolution and the production efficiency of SLSNe as a function of galaxy metallicity over a large redshift interval. After accounting for secular evolution, we find evidence for differential evolution in galaxy mass, but not in the B-band and the far UV luminosity. In addition, we find a dearth of galaxies above 1e10 solar masses, which we attribute to a stifled production efficiency above ~0.4 solar metallicity. H-rich SLSNe are found in a very diverse population of star-forming galaxies. Still, the scarcity of massive hosts suggests a stifled production efficiency above ~0.8 solar metallicity. The large dispersion of the H-rich SLSNe host properties is in stark contrast to those of gamma-ray burst, regular core-collapse SN, and H-poor SLSN host galaxies. We propose that multiple progenitor channels give rise to this sub-class. In addition, we present the first results from integral field spectroscopy of 10 H-poor and H-rich SLSN host galaxies, obtained with the wide-field integral field spectrograph MUSE at the ESO/VLT. We examine the galaxy-group environment and draw conclusions on its impact on the star-formation process in SLSN host-galaxies.