Board Thread:Naruto Discussions/@comment-6975341-20170913230750/@comment-734582-20170915095305

HeiwaSozo wrote: Animals? Really lol...? Don't be asinine, Seelentau. That's a bit of an over exaggeration, but judging from how you respond to people otherwise on this site, I'm not surprised. I agree with him though.

The topic of chakra, spiritual power, lifeforce and Six Paths chakra is complicated and poorly explained. The series has put in very little effort to be consistent in this. It's never explained why certain techniques (like Chibaku Tensei) would even cost lifeforce, and after Nagato such costs are never mentioned again.

It's also completely unexplained why nature energy helps healing (acting as a pseudo-lifeforce) or how lifeforce even relates to healing. After all, Tsunade's healing somehow works with large amounts of chakra and Madara implies Hashirama has strong healing because of his chakra levels.

As a topic, there simply isn't much to go on.

As to animals, there are a few interesting animals (Pain's summons mostly) that appear to have no place in any natural ecosystem in the series. It's also not explained why some dogs can and others can't talk.