The earliest reference we have to unusual animal behavior prior to a significant earthquake is from Greece in 373 BC. Rats, weasels, snakes, and centipedes reportedly left their homes and headed for safety several days before a destructive earthquake. Anecdotal evidence abounds of animals, fish, birds, reptiles, and insects exhibiting strange behavior anywhere from weeks to seconds before an earthquake. However, consistent and reliable behavior prior to seismic events, and a mechanism explaining how it could work, still eludes us. Most, but not all, scientists pursuing this mystery are in China or Japan.
An earthquake forecast was made in China several decades ago, based on small earthquakes and unusual animal activity. Many people chose to sleep outside of their homes and thus were spared when the main earthquake indeed occurred and caused widespread destruction. However, usually no large earthquake follows this type of seismic activity, and unfortunately, many earthquakes are preceded by no precursory events whatsoever. The next large Chinese event was unheralded and many thousands of Chinese died.