Every year in spring, glowing blue light can be seen shining from the ocean around Japan. This light is produced by Hotaru Ika, or Firefly Squid, a tiny species of squid that uses bioluminescence. The squid only lives for one year, and in the spring millions of them swim toward the shores to mate and lay eggs. This is also when fishing boats catch the migrating squid, which are then used in a wide range of dishes.