The upper part of the ant trail in Fig. 1; the ants (on the left) were unable to move along the ceiling and thus could not reach the outlet of the ventilation pipe. Photo taken on 18.09.2016 (Wojciech Stephan).

 
 
  Part of: Rutkowski T, Maák I, Vepsäläinen K, Trigos-Peral G, Stephan W, Wojtaszyn G, Czechowski W (2019) Ants trapped for years in an old bunker; survival by cannibalism and eventual escape. Journal of Hymenoptera Research 72: 177-184. https://doi.org/10.3897/jhr.72.38972