Yeah, there's a similar story about swallowing spiders in one of the Scott Adams books. I think it's in "The Dilbert Future".

He talks about how he always keeps a glass of water on his dresser to take drinks during the night, and he always gulps it down in a sleepy daze without thinking about it. But one night, a series of unusual coincidences happened so that the light was on when he did this and he had occasion to look at the glass, and there was a huge spider floating in it. His conclusion was that it was something more than coincidence. His SO's conclusion was that he's probably swallowed many spiders without knowing it.