I know it's not everyone's cup of tea but I've always found this sort of thing fascinating. Insects in general but also the specifics of behavior altering stimuli such as cordyceps fungi. The fact some cicada can lose their entire abdomen to fungal infection and get turned into flying spore dispersal canisters is an incredible mechanical and evolutionary feat.
I know it's not everyone's cup of tea but I've always found this sort of thing fascinating. Insects in general but also the specifics of behavior altering stimuli such as cordyceps fungi. The fact some cicada can lose their entire abdomen to fungal infection and get turned into flying spore dispersal canisters is an incredible mechanical and evolutionary feat.