Worker piping associated with foraging in undisturbed queenright colonies of honey bees

Worker piping, previously reported only in association with colony disturbance or queenlessness, was seen in undisturbed, queenright colonies. Workers piped by pressing the thorax to the comb, spreading the wings slightly and lifting the abdomen towards the wings, which vibrated noticeably as the bee emitted an audible wail. Pipers wandered throughout the hive for up to 2.5 h, stopping every few seconds to emit a pipe, which lasted about 1 s. The sound showed little frequency modulation, and a fundamental frequency of 330-430 Hz. It appeared to be produced by wing muscle vibrations and to be loaded into the comb by pressing down the thorax. Of three workers whose experiences prior to piping were known, two had been foraging and one had been unloading water collectors. Piping in this context may serve as a foraging-related signal, although its receivers and the information it transmits remain unknown.