Over the past decade deep and wide extragalactic surveys, especially X-ray surveys, have dramatically improved our understanding of the majority populations of active galactic nuclei (AGNs) over most of cosmic time. In this talk I briefly highlight some of the exciting discoveries about AGN ecology (i.e., interactions of supermassive black holes and their environments), focusing on the luminosities, masses, morphologies, colors, and star-formation rates of AGN hosts and non-active galaxies. I also discuss some future prospects on AGN ecology.

In addition, I also present a dynamical analysis of the recently-announced planetary system orbiting the eclipsing magnetic white dwarf HU Aquarii.  We show that the proposed planets are extremely unstable.  This suggests that the HU Aquarii planetary system is either more complicated or significantly different to that proposed, or that it is currently undergoing a significant dynamical destabilisation.  We also re-analyse the discovery data and present alternative and more physically plausible system configurations.