Karrikins are butenolide molecules that were identified in smoke as germination stimulants of many plants that emerge after fire. Since their discovery in 2004, karrikins have been found to affect many aspects of plant development, including seedling photomorphogenesis and root hair growth, putatively because they mimic an unknown endogenous hormone. Karrikin signaling occurs via an F-box protein-mediated mechanism, similar to several other plant hormones and strigolactones in particular. In this seminar, I will present our current understanding of how karrikins are perceived by plants and how karrikin signaling is attenuated through two feedback control mechanisms.