ewww spiders!!!!
i have also heard a story about a SNAKE that came crawling up the aisle on a flight (apparently it was harmless but i dont know if it was true or not)
Qantas was in the news a few months ago also becuase two of their planes seemed to be infested with rats or something and the fumigators/rat catchers were having trouble finding them. Pax and crew had reported seeing rats on various flights.
it was on two of their older 737/767 a/c. they are gone now i hope.
i would lock myself in an overhead locker if i saw something like that on my plane!