Earthquakes are frightening events, striking without notice. But some believe there is an early-warning system: animals.Over the centuries, people have reported seeing animals head for the hills or leave their burrows in the weeks, days or hours before a temblor hits. But is this belief grounded in science? It’s true that animals can sense a quake, usually just minutes before humans do, says Michael Blanpied, associate coordinator of the U.S. Geological Survey Earthquake Hazards Program. Established by Congress in 1977, the program monitors and reports earthquakes, assesses earthquake impacts and hazards, and researches the causes and effects of earthquakes.