Board Thread:Theories and Speculation/@comment-1932060-20171201013626/@comment-1512913-20171205035740

Just because we didn't hear some of those you mentioned talk, doesn't mean they can't. Pain's summons were dead creatures, filler only. Manda 2 was an artificially created enhanced/modified clone of Manda in Kabuto's laboratory, not a natural summoning animal. Huge turtle isn't a summoning animal. Shino's summons barely have brains to talk.

It seems all animals originating from 'mystical' places like Mount Myoboku and Ryuchi Cave, can talk, while others originating from places of human dwelling, are ordinary species akin to real life, just with chakra.