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.”
It and things like it go back forever. I had grad school teachers that say animals don’t think. Obviously they do and its not just monkeys and birds and dolphins. Now the thought processes get more basic as you go down but its all there. dreams and such.