[Stwerp]

To be fair, any animals that use body language (i.e. dogs wagging tails) or sight are communicating electromagnetically (reflected light) in the same we humans communicate electromagnetically. We're not generating our own EM signals, but using tools.

I had a discussion about this a while ago with a friend. There's a really interesting video of a HAM guy who has built a system such that he yells into a microphone which then uses the audio energy to generate an RF pulse that travels out the antenna. All RF energy is generated by the vocal energy. By yelling in pulses, Morse (or whatever) coding can be generated. I think he had used to the communicate between Massachusetts and somewhere in Florida.

Our conclusion as to why don't animals communicate with their own RF energy was your answer that you can't build good antennas from organic material. Evolutionarily, though, it seems like a great advantage!

[kasbah]

>There's a really interesting video of a HAM guy who has built a system such that he yells into a microphone which then uses the audio energy to generate an RF pulse that travels out the antenna.

Fascinating, would love to see that in some distopian sci-fi story. Link for those that are curious: http://hackaday.com/2013/11/26/amateur-radio-transmits-1000-...