Document type: Scientific paper published in the Proceedings of the Royal Society B: Biological Sciences
Authors: , O; Lynch, KE; Allman, DM; Latty, T; White, TE
Abstract in French (translation): A flexible self-protection strategy as an indicator of pain-like states in house crickets
Determining whether insects experience painis a pioneering field of research at the intersection of behavior, cognition, and the philosophy of mind. Interest in this topic has been fueled not only by anatomical discoveries but also by an ever-growing body of behavioral and comparative data. The main theoretical models emphasize behavioral indicators of a pain-like experience, such as flexible and targeted responses to an aggressive stimulus that go beyond simple reflexive withdrawal. In this study, we sought to identify such responses in the house cricket (Acheta domesticus), a species of both evolutionary and commercial importance. Using a fully blinded, within-subjects protocol, we applied noxious heat, harmless tactile contact, or no contact to a single antenna under low- and high-stress environmental conditions, and recorded grooming behavior. The crickets were significantly more likely to groom the antenna that had undergone noxious stimulation and did so for longer than under control or tactile treatment conditions. Grooming also exhibited a distinct temporal profile, with high activity that persisted throughout the initial observation period. Environmental conditions and sex had no effect, indicating that self-protective grooming occurred consistently throughout the experiment. These results provide strong evidence of flexible and targeted self-protection in Orthoptera, thereby filling a major gap in the evidence regarding pain-like states in invertebrates. This strengthens the case for considering insect welfare and has implications for how sensory experience is distributed across the animal kingdom.
Preview: The possibility that insects experience pain is a frontier question at the intersection of behaviour, cognition and philosophy of mind. Interest has been fuelled not only by anatomical discoveries but also by expanding behavioural and comparative evidence. Leading frameworks emphasize behavioural indicators of pain-like experience such as flexible, targeted responses to harm beyond reflexive withdrawal. Here, we tested for such responses in the house cricket (Acheta domesticus), a species of evolutionary and commercial importance. Using a fully blinded, within-subjects design, we applied noxious heat, innocuous tactile contact or no-contact to a single antenna under lower- and higher-stress environmental conditions and recorded grooming behaviour. Crickets were significantly more likely to groom the noxiously stimulated antenna and did so for longer than under control or tactile treatments. Grooming also showed a distinct temporal profile, with elevated activity sustained across the early observation period. Environmental conditions and sex had no effect, indicating that self-protective grooming was expressed consistently throughout. These findings provide robust evidence of flexible, site-directed self-protection in Orthoptera, addressing a key gap in evidence for pain-like states outside vertebrates. This strengthens the case for consideration of insect welfare and bears on how felt experience is distributed across the animal kingdom.
