i, too was raised with this assumption (superstition?) that animals can sense quakes, but to be honest only some of my animals have demonstrated it. when i had several cats at once, one would start acting funny and the others seemed to pick up on it afterward; the same with my dogs. some of them freak out up to a day ahead, which seems to contradict my thinking that it's the vibration/sound/electricity to which they're responding, while others don't react at all unless the humnas start stressing. i usually don't notice the little quakes (less than a 5.0) unless someone alerts me. *smile* i've had both cats and dogs do this freaking-out-ahead-of-time thing, and my friends report that their parrots do it too. (we live in SF where there are quakes all the time, mostly little ones and sometimes a biggie.) seems like a hard thing to test scientifically...

I was reading an article once (some random science magazine that my geologist stepdad subscribes to) about how they tested dogs and the whole earthquake thing. They found that it might be that dogs hear a coming earthquake. As we all know they can hear a huge range of sounds. As it turns out, rocks under the surface make a lot of noise before an earthquake actually occurs...humans just can't hear it. They found that dogs that are deaf don't react at all, dogs with large ear flaps don't react very much and the dogs that react the most are the ones with upright ears. It's not a "6th sense" at all but their crazy hearing ability.

I too live in the SF Bay Area, and the last large one we had, our one dog with the upright ears had been acting very strange all day (refusing to come in the house and then when we would finally get him inside he only wanted to go back out, which is the exact opposite of how he is every other day), while our female with the floppy ears didn't react that much at all.