Oviduct fluid extracellular vesicles help control the number of sperm entering pig eggs during in vitro fertilization. By adding these vesicles to the fertilization process, researchers found they could reduce the chances of multiple sperm fertilizing the same egg without affecting the overall fertilization rate. The vesicles, which are tiny structures released by cells, contain proteins that are important for early reproductive events. This study suggests that using these vesicles as a supplement during in vitro fertilization could improve the success of creating pig embryos in the lab.