Are humans the only animals to have language? It’s proven to be a fraught question. Sperm whales certainly have “coda” (clicks issued in distinctive, often repeated patterns), and the Cetacean Translation Initiative—Project ceti for short, is attempting to record and decipher it. Elizabeth Kolbert tags along with the team for some trips, and has some extraordinary experiences.

The world’s largest predators, sperm whales spend most of their lives hunting. To find their prey—generally squid—in the darkness of the depths, they rely on echolocation. By means of a specialized organ in their heads, they generate streams of clicks that bounce off any solid (or semi-solid) object. Sperm whales also produce quick bursts of clicks, known as codas, which they exchange with one another. The exchanges seem to have the structure of conversation.