Don’t reach for the bug spray: scientists find insects may feel pain after crickets nurse sore antenna

Do insects feel pain? Crickets certainly seem to, according to new research which finds they stroke and groom a sore antenna in much the same way as a dog nurses its hurt paw. 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. But evidence for pain is difficult to establish in other species, he says, so scientists look for behavioural cues. One indicator is “flexible self-protection”, where an animal directs protection to a particular body part over an extended period of time. “You see a dog, limping, or licking its paw, or holding one particular arm – of course, we’d immediately say, well that’s in pain, it must be sore.” Scientists search for evidence of similar responses to ascribe pain to other animals, including insects. So, to test the idea in crickets, researchers first had to give them an “ouchy”. In the study, published in Proceedings of the Royal Society, dozens of crickets were randomly selected to receive one of three treatments. Some had a heated soldering iron applied to one antenna, while other crickets received the same probe; unheated, and a third acted as a control. The soldering iron was set to 65C – hot enough to be a “bit unpleasant”, without causing lasting harm, White says. …