The behavioural cue of ‘flexible self-protection’ is a way to establish whether an animal feels pain, scientists say

Crickets that received the hot probe “overwhelmingly” directed their attention to the affected antenna – they groomed it more frequently, and tended to it over a longer period of time, he says. “They weren’t just agitated and flustered. They were directing their attention to the actual antennae that was hit with this hot probe.”

Link to the paper