Before the Haicheng earthquake in China in 1975, snakes were seen to leave their underground holes despite the cold of winter and froze to death on the surface. Based on further observations and numerous foreshocks, the city was successfully evacuated before the earthquake occurred. Owing to the Cultural Revolution, little reliable information about these observations ever reached the public domain. And in spite of the success in forecasting the 1975 quake, there was no advance warning given before the Tangshan earthquake that occurred the following year.
Sources: Bhargava, Katiyar, Sharma, & Pradhan, 2009; Kanamori, 2001