Humans have yet to completely understand how they perceive their environment, much less how other organisms do. — skyblack

Yes, but humans are pretty complex relatively when contrasted with other simple living organisms. A human brain has 86 billion neurons whereas a roundworm has just 300 neurons. Makes one wonder in this case - should understanding come from deciphering simple organisms or from understanding ourselves and then dumbing it down to simpler organisms? Maybe the former is for the scientists and the latter is for philosophers?

Then the question may be, language being limited, therefore thought/thinking being limited, cannot contain anything that is beyond language. Therefore it cannot contain silence. There can never be a language of silence. — skyblack

I don't think so. If thought can be described as "that allows humans to make sense of, interpret, represent or model the world they experience, and to make predictions about that world." In nature, we see a lot of animals which rely just on this definition to survive and do stuff. We see living organisms communicating through sounds, chemical signals, gestures, and so on all the time. Our species is just one experiment out of millions of species that nature tried.

Again, it is possible that our language might be playing tricks on us into thinking that we actually understand something that we clearly don't.