Abstract: Direct detection experiments looking for sub-GeV dark matter (DM) through nuclear recoils have already placed constraints down to DM masses ~ 100 MeV with energy thresholds of ~ 10 eV. Challenges in achieving sensitivity to lower DM masses include precisely calculating the DM scattering rates through multi-phonons, and understanding as well as mitigating backgrounds in low-threshold detectors. In this seminar, I will consider both these aspects of direct detection, and talk about signal calculations for MeV-100 MeV DM and new backgrounds at the energy scales being targeted in the near-future experiments below the current thresholds.