That question had been on my mind ever since we ran into the guardian beasts for the first time. I hadn't given it too much thought back then, and I had always assumed that the reason why I could only understand the mother was because of the cub's young age. But after seeing the other two bixie children today, I realized that this assumption couldn't hold anymore. Those two were fully grown already, yet I still couldn't figure out the meaning of any sound they made.