A capt I flew w last week told me a story about getting on an empty airplane. He went back to use the lav and a bird popped up from behind a seat and flew into the cockpit. He came out of the lav and looked around, saw no bird, thought nothing more about it. Pushback, check the rudder and low and behold the bird comes out of the pedals and flies smack into the capts face. then disapears back into the pedals. They end up having mx come out, open all the windows and doors, remove the fms's, open the avionics bay and access panels and flushed the thing out. Crazy story and a good thing it happened on the ramp and not at v1.