Being jolted awake every morning by an alarm clock is plenty annoying, but at least that alarm doesn’t actually live in your body. The Hawaiian bobtail squid (Euprymna scolopes) has an internal alarm clock that’s run by a species of glowing bacteria known as Vibrio fischeri. This bacterium and the squid are symbiotic, which means the two...

Being jolted awake every morning by an alarm clock is plenty annoying, but at least that alarm doesn’t actually live in your body. The Hawaiian bobtail squid (Euprymna scolopes) has an internal alarm clock that’s run by a species of glowing bacteria known as Vibrio fischeri. This bacterium and the squid are symbiotic, which means the two...