Busy Ants Form Black Line in Traveller's Room

Occurred on June 2022 / Chumpon, Thailand

Info from Licensor: "I had a vacation in Chumpon, Thailand. This was in June 2022. When I was going to bed, I saw this black line outside my room. The black line was termites. They were gone the next morning, but left a black mark on the floor. I found this really interesting and just stared at it for minutes."