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 　　Adult ants communicate with pheromones, touch and even sound. Now researchers have discovered that developing ants called pupae have their own distinctive¹ calls, which identify their social status within the colony. This finding is in the journal Current Biology. Ants rasp and chirp² by scraping a spite on their waist against a ridged section of their abdomen³, but developing larvae⁴ are silent. So ants recognise them by chemical cues, size, shape and even squishiness. The teenage versions of ants, the pupae, have hard outer shells that lack pheromones. However, the pupae do have fully⁵ formed sound organs. The researchers thus record the audio from the pupae and discover clicking noises. The pulses' frequency and intensity⁶ are more like the adult worker's stridulations than the queen ant's sound. The pupae's snaps are brief because their cases keep them from moving much. Still the noise appears to work, when the researcher disturb the nest, the adult ants rescue noisy pupae before the silent larvae. For ants, as for people, it pays to be the squeaky wheal.