I'm just chock full of these random things lately, aren't I? Any of you radio folks out there might be able to shed some light on this for me. Imagine a creature with some sort of ferrous appendage or body part (Say, it's spinal cord or some other lateral formation). Given the right circumstances and biological functions, could it act as a radio antenna for transmitting or receiving? Not that these signals would be travelling very far, or have much power. Speaking of power, how much would be needed for this kind of communication? (Say, one kilometer?) There exist organisms on Earth that can biologically generate high-voltage currents (Electric eels, for one), so it's not out of the realm of possibility. A radio transmitter requires a modulator circuit, for which I believe the animal's brain could work. I don't know about organic amplifiers or impedance matchers, as I don't understand exactly how they work. Forget whatever evolutionary limitations you know of for a moment, all I want to find out is if this is possible. If we deem it possible, I'd like to go into more detail with this theory. But that's for a later date, first things first. Is it possible?