The upper part of the bunker space with the F. polyctena ‘nest’. In the middle of the ceiling, the input of the ventilation pipe. Ants climbing walls (and hardly reaching the ceiling) en masse within and outside the room are visible (especially well on the door frame). Photo taken on 24.07.2015 (Wojciech Stephan).

 
 
  Part of: Czechowski W, Rutkowski T, Stephan W, Vepsäläinen K (2016) Living beyond the limits of survival: wood ants trapped in a gigantic pitfall. Journal of Hymenoptera Research 51: 227-239. https://doi.org/10.3897/jhr.51.9096