I don't know how it works -- if it's cool outside, I guess the fan could be sucking air in from the outside and blowing it on the server, and if it's hot outside the fan could be sucking the hot air away from the server and blowing it outside.
I think it went the other way around. Bloch got the idea from the legend. The reason we call them "earwigs" is that our ancient Anglo-Saxon ancestors thought they would get into your ear and wiggle around. (The etymological info comes from the Oxford English Dictionary, so it's reliable.)
It goes across cultures too. The French call it a "perce-oreille" and the Germans call it an "ohr-wurm," both based on the belief that the insect burrows into people's ears.
Jack Rabbit is onlly saying that because they've ALREADY TAKEN OVER HIS BRAIN!