Due to the human propensity to build cities near freshwater, river ecosystems are disproportionally exposed to artificial light at night (ALAN) compared to other ecosystems. Benthic invertebrates play a critical role in lotic ecosystems, as they are an important food source for fish and birds, as well as maintain water quality. Because they are more active at night, when the chance for detection by visual predators is low, one may expect benthic invertebrate activity to decrease under exposure to ALAN. However, studies on benthic invertebrate activity under ALAN have shown mixed responses. One potential explanation for these contradictory results is adaptation or acclimation to ALAN. I will present results from a recent study of benthic invertebrate activity across an ALAN gradient, and will discuss its implications for stream ecosystems as a whole.