Honestly, yukkuri are big balls of talking play-dough with extremely odd talking habits and mindsets. If I was a kid, fuck, I'd poke it too. Animals are one thing but what do you even do about THESE things?
YukkurisMustDie said: But yukkuris aren't animals. Their lives mean nothing.
It's more like "things" rather than yukkuri specific. The kids seems like he still doesn't really understand the different between yukkuri, animal, or just any animate object. He'll probably poke a Chupacabra if he saw one.
...worse is even younger kids, they seems to have the same logic of understanding the world as sharks and crocs: When in doubt, munch munch it. Resulting in that familiar warning of "chocking hazard, not for children under 3 years"