The 50-50-90 rule: Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong.
Question #78720 posted on 08/16/2014 11:30 a.m.
Q:

Dear 100 Hour Board,

Why don't my kitty cats get fleas here in Utah (located along the bench of the Wasatch Front in Utah County), but they sure did in the Sacramento area of California? Is it elevation? Do fleas not exist at high elevations?

-Snoop Catt

A:

Dear friend,

Though fleas are not entirely unheard of in Utah, by and large the climate is too dry and too cold for them to thrive. The little suckers (ha, see what I did there?) prefer warm, humid locales, which keeps Utah relatively flea-free. 

Peace,

-Stego Lily

Sources:

http://extension.usu.edu/files/publications/factsheet/flea08.pdf
http://www.deseretnews.com/article/600152710/Fears-that-Fido-has-fleas-are-unfounded.html?pg=all