Here’s a neat article about squid — it appears that they can control the polarization of light that bounces off of their skin, allowing them to send ‘secret’ messages that are only visible to the few other animals capable of detecting polarization. It’s not that uncommon for creatures to communicate using signals that others (ok, I’m thinking mostly human here) aren’t aware of, such as ultrasonic bat songs or the nuanced pheromones of insects, however the fact that squid are using light seems fascinating.

Now I want to make some robots that communicate by polarizing light! Anyone out there working on this already? [Via Schneier on Security]

Longfin Inshore Squid photo adopted from Wikipedia user Citron.