Abnormal behaviour in rats and various other animals has been seen immediately before damaging tremors. There is a potential physical explanation for such unusual behaviour: every earthquake radiates P and S waves. P (primary) waves travel faster than S (secondary) waves, which in major quakes cause clearly noticeable, damaging tremors. Animals that already feel incoming P waves may, under some circumstances, react before the S waves arrive shortly thereafter.
Source: Bhargava et al., 2009