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.”
75% decline of flying insects population in germany
https://edition.cnn.com/2017/10/19/europe/insect-decline-germany/
For what it’s worth, my totally non scientific personal experience is that in Denmark, the number of insects that I have to clean off the car has trended upwards in the last two years