Crickets Show Signs of Pain by Grooming Injured Antennae

Crickets appear to experience pain, according to research that found the insects stroke and groom a sore antenna after injury in a similar way to how a dog nurses a hurt paw. The study identified the behavioural cue of flexible self-protection as a method to establish whether an animal feels pain.

Associate Prof Thomas White, an entomologist from the University of Sydney, said the experience of pain was a longer, drawn-out, ouchy feeling that differed from a hardwired nerve response. Scientists have long debated whether insects feel pain or simply exhibit automatic reflexes to harmful stimuli.

The new findings add to evidence that some insects may have the capacity for pain perception beyond basic avoidance reactions.

The observation comes from experiments in which crickets sustained antenna injuries. Researchers noted the insects' subsequent grooming behaviour targeted the affected area in a deliberate and sustained manner. This type of self-directed care has been documented in other animals known to feel pain.

The study's authors suggest the crickets' actions indicate a form of protective behaviour that is flexible rather than purely reflexive. White explained that distinguishing pain from reflex responses requires looking for behaviours that go beyond immediate withdrawal.

The grooming observed in the crickets fits this criterion according to the research criteria.