Jeff Corwin lies.
MSNBC's Chris Jansing interviewed the celebrity biologist yesterday as part of a news story about spider silk. As the segment closed, Corwin told Jansing that the average person swallows 10 spiders while sleeping during the course of a year. When Jansing asked if that was really true, he said "Ask any wildlife biologist!"
The University of Idaho calls this "total nonsense." The University of Washington says it has "no basis in fact." This urban legend was, in fact, started intentionally by someone who was trying to prove how gullible people can be.
I guess Jeff Corwin is just really gullible. Not exactly a trait you'd expect from a scientist.