The landmark discovery was made at a crocodile farm, where scientists observed the four and three alligators, cayman (all - close relatives of crocodiles). Reptiles eat their meat on the ground: it was the usual method of feeding predators, so zoologists and arrived at the farm. Under natural conditions - in the muddy water - to monitor the eyes of crocodiles would be difficult. Observations showed that the eyes of five of the seven reptiles during the meal tears flowed.

The study was conducted at the request of doctors-neurologists from the University of California at Los Angeles, studying a rare syndrome called "crocodile tears" (some people are crying for an unknown reason during the meal).

In the preparation of scientific articles, physicians interested in causes the appearance of the term "crocodile tears": it was important to determine whether this phenomenon really is and if so, what it is due. As a result, neurologists from California contacted by zoologists from Florida.

Those interested in the problem and soon discovered that in the scientific literature has many references to this phenomenon, however, mostly anecdotal.

According to them, the first mention of crocodile tears found in the book "The Journey of Sir John Mandelane", first published in England sometime between 1357 and 1371 years. In this book, apparently written by a Frenchman from Normandy, describes the trip to Asia, the Middle East and Africa. Most of the facts contained therein are based on the works of real travel (eg, Plano Carpini) and historians (eg, Getuma), it also contains many stories about the Amazons, people with dogs' heads and other miracles. The book was extremely popular in Europe, it, in particular, read by Christopher Columbus. The book contains the following passage: "in this country (Ethiopia) lives a lot of crocodiles, who weep when eaten by man."

Zoologists have been denied the opportunity to feed guinea crocodiles human flesh, so replaced it with the usual beef. Causes of crocodile tears while not known for certain.