Growing up in the Seattle area I went through several - including the 1963 earthquake that did quite a bit of damage. I remember parts of my school fell down, our dishes fell out of our cupboards and our lamps fell over and broke. My mother made us all kneel down in the doorways and say hail marys, then we got in the car, saw the broken roads, and went to see the fallen school....and that's how I remember it as a very young child! No fear, just amazement.
(Okay, all physicists and geologist, stop reading here...I am going to use bad science descriptions here, bear with me for the sake of analogies).
There are essentially two "kinds" of earthquakes- shakers or rollers (depends on how the plates are shifting and where you are in relation to the plate shift/fault line). Rollers are just that- the ground moves in a wave like form and it feels like surfing or rolling. These can get pretty big without damage as long as the waves are far apart and gentle. Shakers twist, so to speak, and thus can really torque a building. Think of grabbing a building by opposite corners and shaking it back and forth and twisting- even small shakers can do some damage (and a big one can do lots of damage).
An earthquake can also be a shaker and a roller at the same time, depending on where you are in relation to the fault line, what kind of "base" you are sitting on (sand, gravel or rock), and how deep the quake is.
Animals sense the quakes before we do because many can "hear" the ultrasonic or subsonic sounds of the earth movement before we do- thus they don't predict it, but just react to it sooner!
Last year we had a 5.0ish quake here in the midwest. I remember it being about 5 AM, and thinking, "oh, no problem, just a little quake", and rolling over, then realizing "what the #$$Q#$....I am in ILLINOIS not SEATTLE!!!!!"....sure took me by surprise. We had several aftershocks during the day and my university students would actually scream when the building shook----wimps!
All that being said, as a transplant to the midwest for the last 22 years- give me a good earthquake ANY day over these gosh darn tornado things! I still get terrified at the tornado warnings, but I kind of enjoy a good 4.5-5.5 tremblor!!!!