A sub-component of dark matter with a short collision length compared to a planetary size leads to efficient accumulation of dark matter in astrophysical bodies. Such particles represent an interesting physics target since they can evade existing bounds from direct detection due to their rapid thermalization in high-density environments. In this talk, I will show that their annihilation to visible matter inside large-volume neutrino telescopes can provide a novel way to constrain or discover such particles. The signal is the most pronounced for relic masses in the GeV range, and can be efficiently constrained by existing Super-Kamiokande searches for dinucleon annihilation. I will also talk about possible neutrino signals from the annihilation of such dark matter particles, demonstrating that neutrino signals from the center of the Earth provide sensitivity to the unexplored parts of the parameter space. 

In this talk I will talk about my recent article where we propose a simpler way to combine the seesaw and the scotogenic approaches, by making dark matter the seed of neutrino mass generation within a low-scale seesaw mechanism. For definiteness we take the inverse seesaw as our template. I will discuss thoroughly both the possibilities of explicit as well as dynamical lepton number violation. For the case of dynamical lepton number violation I will discuss in some detail the phenomenology of invisible Higgs decays with majoron emission, as well as the phenomenology of scotogenic WIMP dark matter.