Snapshots of a fast evacuation process.

<p>Input voltage was 50 V. Frames at time (A<b>)</b> 2 min 11 s, (B) 3 min 10 s, <b>(C)</b> 4 min 25 s, (D) 5 min 30 s. The red-dashed line at 0.75 cm from the door limits the area where the density shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g005" target="_blank">Fig.5</a> B is measured.</p

Time evolution of chamber B floor temperature.

<p>This is the punishable chamber and the temperature was measured by the integrated circuit LM335z (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g002" target="_blank">Fig.2</a>).</p

Individual Trajectories.

<p>The 4 panels show 4 arbitrary sets of randomly chosen trajectories during one of the quickest evacuation process (same trial as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g004" target="_blank">Fig. 4</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g004" target="_blank">5</a>).</p

Arena scheme.

<p>The shaded area (chamber B) is the room with aluminum floor, areas (c) to (h) are a single piece of synthetic rubber and the remaining pieces are made of glass. The piston (p) is used for pushing ants to the punishable chamber. Measurements (x, y, z): (a) – (b): 14.5 cm×14 cm×2 mm, (c): 1 cm×9 cm×1.5 mm (d) – (e): 26 cm×1 cm×1.5 mm (f) – (g): 3 cm×4 cm×1.5 mm, (h) – (i): 1.5 cm×4.4 cm×1.5 mm, (j) – (k): 24 cm×2 cm×4 mm. Exit width: 2 mm.</p

Bottom view of the arena.

<p>Positions of the heat source and the three thermometers used under the aluminum plate.</p

Evolution of population and density for the same trial shown in Fig. 4.

<p>(A) Population inside the punishable chamber as a function of time. (B) Evolution of the density near the door in the area of 1.5 cm² limited by the walls and the red-dashed line in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g004" target="_blank">Fig. 4</a>. The red line at 33 ants/cm² is the approximated maximum achievable ant density considering an ant body of 0.03 cm² in a close packing. In both panels the arrows indicate the frames of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081082#pone-0081082-g004" target="_blank">Fig. 4</a>.</p