Cutouts of all HzRG 24   μm  fields with a 3σ significance source overdensity. The dotted circle represents the 1.75′ radius circular sub-field that is analysed further, and plotted in red are the source for which f_24   μm ≥ 0.3 mJy. All fields are scaled to the same 5.8′ × 5.8′ angular size, with North/East facing up/left. The HzRG is plotted as a blue star in each frame. Note that PKS1138-262 is much deeper GTO data. A colour counterpart is available in the online version of this article.