" The squid has even evolved a special place to house the bacteria - a structure scientists call a 'light organ' located inside the mantle. But the bacteria don't just set up house and begin to party. When the first batch of bacteria arrive in their new digs, they have work to do.The light organ has been partially prepared for the bacteria's arrival, but the final touches won't occur until the newly arrived bacteria get things started. It's as though they've arrived in a new house but only the frame is up. The bacteria themselves have to do the finish work. "

― , Kraken: The Curious, Exciting, and Slightly Disturbing Science of Squid