Now, the ins and outs of Yukkuri pets have been explored to the most minute detail in nigh infinite stories: mostly treated like mouses (can be pets or pests depending on their status, and can hop that barrier pretty easily). This is pretty nice, I guess; Yukkuris are not intelligent enough to grant much more, even if I guess speech would do a lot to miff many people about extermination, even when insultive.
But. What about bodied Yukkuris? Even if the line is very fluid, as with everything related to the argument, they are constantly more clever than adult Yukkuris, even when still young; the bar goes higher and higher, up to the Reisen in RBY/GSC who starts at least at the intellect of a 6-years-old and does nothing but mature intellectually.
I expect most grown up bodied Yukkuri, then, to be at least as intelligent as a kid of 10-15 years, mostly capable to care for themselves, to recognize others and to learn stuff of moderate complexity. What does this make of possible pet status? I don't think the concept of ownership - or abyuse! - would be barely as accepted as for the most common model.
Updated by BaronMind