Konchu are roly-poly sorts of small bugs. They're like centipedes. They will leap at you to attack you with their large claws, or they'll roll up in a ball to roll at you and bowl you over. Konchu will bounce all weapons when roaming around in the natural state. Hitting them causes them to ball up and them flop onto their back, revealing their soft undersides. This is when you can attack to kill them! Note that poison will not preserve Konchu's body, attack them normally to leave a carveable body.
Konchu are surprisingly dangerous for their small size. It's not uncommon for them to latch onto large monsters' body parts as protection (even though it doesn't benefit them). Unaware hunters attacking that body part will bounce, leaving them very open for getting a face full of boss monster.