As a follow-up to the IPS 2016 symposium “Burning the midnight oil: great ape nocturnal activity and the implications for human evolution” we investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors. Data were extracted from terrestrial camera trap footage and ecological surveys at 22 chimpanzee study sites participating in the PanAfrican Programme: The Cultured Chimpanzee. From videos demonstrating nocturnal activity, we investigated the effects of percentage of forest, abundance of predators (lions, leopards, hyenas), abundance of large mammals (buffalos, elephants), average daily temperature, rainfall, human activity, and percent illumination. Terrestrial nocturnal activity occurred at 18 sites, at an overall average proportion of 1.80% of chimpanzee activity, and during all hours of the night. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of closed forest (full-null model: χ2=28.762, df=8, p=0.001). Abundance of predators and large mammals, rainfall, and moon illumination had no effect. Thus, chimpanzee terrestrial nocturnal activity appears infrequent, suggesting a consolidated sleeping pattern. Together with evidence that sleep in traditional societies is consolidated, our results suggest that ancestral human sleep was also consolidated. Chimpanzee nocturnal activity appears flexible, enabling response to fluctuating external pressures. Such flexibility can allow species to adapt to changing environments.