Lars Chittka at Scientific American:
The conventional wisdom about insects has been that they are automatons—unthinking, unfeeling creatures whose behavior is entirely hardwired. But in the 1990s researchers began making startling discoveries about insect minds. It’s not just the bees. Some species of wasps recognize their nest mates’ faces and acquire impressive social skills. For example, they can infer the fighting strengths of other wasps relative to their own just by watching other wasps fight among themselves. Ants rescue nest mates buried under rubble, digging away only over trapped (and thus invisible) body parts, inferring the body dimension from those parts that are visible above the surface. Flies immersed in virtual reality display attention and awareness of the passing of time. Locusts can visually estimate rung distances when walking on a ladder and then plan their step width accordingly (even when the target is hidden from sight after the movement is initiated).
Given the substantial work on the sophistication of insect cognition, it might seem surprising that it took scientists so long to ask whether, if some insects are that smart, perhaps they could also be sentient, capable of feeling.
more here.