Anecdote: When courtship blurs: a case of male-directed sexual signaling in house crickets (Acheta domesticus)

Same-sex sexual behaviour has been reported across diverse animal taxa and is increasingly understood as a flexible outcome of sexual signaling rather than an evolutionary anomaly. In insects, such behaviours are often temporary, context dependent, and expressed alongside opposite-sex courtship. This pattern has led to increasing emphasis on condition-dependent mating filters, defined as how selectively individuals direct sexual signals toward potential mates. Here, I report a rare and, to my knowledge, first observation of male-directed sexual signaling in the house cricket (Acheta domesticus). In a video recorded during routine behavioural assays, an adult male produced sexual acoustic signals, courtship calls, toward another male. Simultaneously, this male directed aggressive signals toward other individuals within the same arena. This behaviour occurred under standardized laboratory conditions with a high-quality diet, ruling out nutritional stress as an explanation. Notably, the individuals involved originated from highly inbred laboratory lines, suggesting that extreme homozygosity may represent an overlooked source of variation influencing sexual signaling. This observation highlights the value of documenting rare behaviours and suggests new avenues for exploring the role of genetic context in mating filters and sexual communication.