North Korea has sent at least 260 bubbles over the borders into the South, scattering suspected feces, dirt and advertising flyers.
South Korea sent the army out to examine and collect the aircraft after warning the people about the uncomfortable flying arrival.
Since the Korean War in the 1950s, the two nations have both used bubbles to distribute advertising.
What are the most recent improvements, according to Shaimaa Khalil of the BBC.