At www.technologyreview.com/blog/arxiv/ April 25th (Physics blog) 'How Bacteria could generate radio waves' (or go to www.technologyreview.com and click on blogs along the top menu, then click on the Physics blog which is usually the first one to pop up). arxiv.org/abs/1104.3113 'Eelctromagnetic signals from bacterial DNA' … natural sources for radio waves include lightning, stars and pulsars and artificial sources include radar, mobile phones and computers etc. It seems some types of bacterial DNA take the form of circular loops, modelling the behaviour of free electrons moving around a loop etc. Actual radio signals are broadcast – by E Coli bacteria. However, the discovery is controversial and is not accepted by many mainstream biologists – so it may in effect be pie in the sky. However, it is known that bacteria as well as cells use electromagnetic waves at high frequencies to communicate and to send and store energy.