Cannibalism is a major limitation to the culture of several commercially valuable crustaceans, including the tropical rock lobster, Panulirus ornatus. Cannibalism of vulnerable, soft-bodied, moulting lobsters is common during the early juvenile stage of culture, as they experience frequent moulting to facilitate growth. Our research has quantified the contribution of cannibalism to juvenile mortality, as high as 50% per 30 days, and investigated the external triggers and internal pathways responsible for mediating this behaviour. Extensive observation of tank populations demonstrated a marked increase in locomotor activity in advance of moulting lobsters being cannibalised, revealing the drivers of this behaviour are present and received by cannibals at least an hour before. Differential expression analysis and enrichment analysis of P. ornatus olfactory tissue reveals upregulation and enrichment of ionotropic receptors, previously found to mediate odorant input and olfactory signalling. Further investigation through choice flume bioassays reveals chemoreception via the lateral antennule flagellum is vital for cannibal-prey recognition. Chemicals released by moulting lobsters and those present in their haemolymph, are being investigated as possible cues alerting potential cannibals to a vulnerable target. This research is fundamental to understanding a common behaviour which limits culture production for several important species.