When yukkuris use their tongue to touch an object.
Usually done as a comforting action to other yukkuris.
Yukkuris use their tongues for many things, including giving comfort to their children and siblings. For example, parents and siblings might lick their loved ones to make them relax or even lick their anyarus to allow them to shit easily.
The latter is important as new born yukkuris do not have body strenght to defecate on their own. By licking their anyarus, parents stimulate and relax the koyukkuris' bodies, allowing them to shit easily.