And humans don't communicate with each other by frequencies of light undetectable to the eye. What happens is we digitalize the ways in which we communicate and send them via radio were they are reproduced in forms sensible to a human being. Which is exactly the way advanced insects would communicate over long distances. The reason radio is used is because it is the fastest way to communicate (perhaps spin can allow you to communicate instantaneously but if aliens are communicating this way, it would be undetectable to anyone outside of the system so if aliens were trying to prodcast there existence they would use light). Oh, and if you say "smell can't be produced artificially" you'd be wrong.Phoenix said:The use of radio is perhaps one of the worse ways to intentionally try to signal other intelligent species. Radio is subject to a wide variety of distortions and easily gets lost in the noise of all of the other radio signals produced by everything else in the known universe. The thought that a species would use radio is again based on the firm, yet stupid, assumption that an intelligent species would follow our evolutionary path. If I'm an insectoid that communicated through scent or pheremones.