"Although darkness has long been associated with insecurity, the link remains speculative. I fill the gap by examining the effect of solar eclipses on political violence. Expanding on psychological theories, I hypothesize that eclipse-induced darkness evokes fear, which in turn is misattributed to outgroups, thereby triggering violence. I contrast this argument with a tactical explanation, suggesting that the darkness allows insurgents to secretly kill civilians. I test these hypotheses by exploiting exogenous variations in the dates and locations of solar eclipses for 1997–2022 in Africa. The analysis indicates a spike in violence on the days of solar eclipses. To explore the mechanisms, I examine the initiators and original texts of violent events, weather conditions, ethnic folklore, and individual-level surveys. The analyses consistently support the tactical rather than psychological explanation. These findings warn against assuming that “irrational” African people overreacted to eclipses; insurgents rationally used darkness for their purposes."