It would be possible, but consider, the mouth would be one of the most undesirable places for a spider there is.
There is a common urban myth that you eat spiders in your sleep, and it it just not true.
No spider is willingly going to crawl into your mouth.
http://www.burkemuseum.org/spidermyth/my...
This site has loads of these ridiculous myths, often inciting fear of spiders, the truth is here.
Spiders can crawl in your mouth and nose, but most residential-area spiders wouldn't want to.
Here's the snopes on that whole "spiders-eaten-per-year" thing. Summary: it's a myth.
(there's a picture on the top of that website, so if you're arachnophobic then proceed with caution)
Spiders are not going to crawl near a human mouth. Spiders go in flight mode when they hear the breath of a human, thus, spiders won't crawl in your mouth when you sleep. Eitherway, if a spider manages to get deep enough into your mouth, your vomit reflexes kick in even in your sleep. Thus you cannot unvoluntarily swallow a spider.
Nothing to worry about. :)
I guess they could but I don't think they like the smell of carbon dioxide
No they cannot, Mr. Paranoid.
no but this dick can
what about when you have a blocked nose?
