Bats (aren't bugs! for those c+h fans out there)

http://dsc.discovery.com/news/2007/10/31/bat-calls-behavior.html

I remember musing in class on whether the concept of naming (remember this discussion?) and the associated idea of identity were unique to humans, and were therefore the source of our singular consciousness of consciousness (heh...that is to say, we are aware of our consciousness). I still wonder about the second part, but the first claim is easily disproven. This article deals with bat language and identity calls. The only discernible difference between bat calls is the voice of any individual bat, but apparently, twin baby bats sound exactly the same, so by their voices alone are indistinguishable to a mother bat who may need to nurse or feed one or the other. So to uniquely identify themselves, the twins emit different "isolation" calls which are different in the actual pitches of the call. In fact, all pup bats do this isolation thing, suggesting that they are, in essence, naming themselves.

But does this constitute a "name"? The question to ask here is whether the bats know that emitting this call identifies them, or it's just an instinctive thing to do. And then determining whether a bat is aware of its identity could hinge on the answer to that question. Since there's no bidirectionality (i think) of this naming convention - like, the mom doesn't emit the isolation call of some pup to get its attention - then I think the pups aren't aware of the function of their call. They just cry it to get mom's attention. On the other hand, the mom probably knows the function of the call since she associates calls with pups, so to her the call is a name. Therefore, the mom is aware of someone else's identity, so by differentiation would she then be aware of herself in relation to others?

Enough of that, more topical now - clearly the bats have a verbalized language with possibly differentiated "words" (calls for food or nursing)...the anthro question is whether human language develops along the same lines? Because the bats definitely didn't form a committee to create a language, so do humans naturally and instinctively generate language? I always have wondered whether at some point cavemen got together in a town hall (or cave) and decided that cow meant cow, etc., or if somehow over vast geographical expanses the random grunts of different individuals organically took on meaning, syntax, grammar. Anyone know the answer?