Fig. 2.

Subordinates enhance responses to pup vocalizations by eating the pregnant queen’s feces. (A) Schematic diagram of food pellet placement and two-choice test. We conducted the test four times in 14 d and placed the pellets containing pregnant queen’s feces in the colony for 9 d (pink, from day 2 to day 10). (B–D) The approach response of subordinates to the sound (black) and no-sound (white) side of the tube at different time points: before (day 1, n = 5), during 1 (day 5, n = 5), during 2 (day 10, n = 5), and after (day 14, n = 5). (B) Latency to enter a tube. (C) Time spent inside a tube. (D) Time subordinates spent searching the mesh. After consuming the pellets, subordinates approached the side emitting the reproduced pup’s voice more frequently than the silent side of the tube. **P < 0.01. Data are represented as mean ± SEM.