Yes, any sensible Yukkuri should bite humans instead of "puff-puff", the reason why we are wary of stray dogs is they can bit when threatened. If more yukkuris would bite when in danger then humans would have to at least think a bit before messing with them.
Hasn't [Patchy] taught you everything about wipe-wipe!?*Fart**Crush!!*Kyuu!!?*Flow*Hurts-!!
...Ah, actually doesn't hurt at all*Chomp!!*Mokyah!!A-aside from this, protect the little one!!Yukkuris' excretion:
They basically forget everything after eating-shitting-sleeping
(Or reset themselves)L-little one is acting like a fool?!W-w-w-what's wrong with this?*Roll!**Slap!*YuuNio!Eajy jy jy jy...*Flap! Flap!*D-dwo cwean-cwean!Why ish pee-pee getting on mishter fache!?Pee-pee too!
Can'ch chake it eajy!Poo-poo came ouch!