The ongoing conflict in Ukraine is often described as the world's "first drone war". It has led to a continuing huge growth in the production of military drones, both within and outside Ukraine. Before Russia's invasion of Ukraine Kseniia Kalmus was a floral artist. She co-owned a flower shop in Kyiv and travelled around Europe showcasing her floral arrangements. Now, she makes drones for use against the Russians. "It was just an obvious decision for me," she tells the BBC from the Ukrainian