It just occured to me , but Yukkuri crawling along like snails makes very little sense. There would be too much friction to allow effective locomotion. Unless you want to entertain the possibility of slimey yukkuri ...
That's true, though that friction may be the reason why they bounce around, as we had seen, even adults crawl slowly, so maybe crawl is like their walking while bouncing is like their running or faster walking.
Ah forgot to mention this, it's either walking or the proportionate of walking in 4 legs for bipedal animals, while bounce may be the real walking.
Which makes sense if you make paralels of young aka yukkuri (baby yukkuri) = can't bounce only crawl, and that "Stealth" Mode (sarcasmn modo activated because of the yukkuris stealth stats) of the adults is usually crawling or walking slowly and with crouching.