Have people eaten hair in there food and never know about it?!

Absolutely! As a matter of fact we eat hair all the time. The FDA & USDA expect that nearly every type of food that is prepared (especially grains) has rodent hair in it. This is an extremely low percentage but it is a known fact that is accepted. Furthermore, human facial hair & hair off of their arms will always get into the food unless the preparer is wearing protective clothing. (but then there's eye lashes). Lastly, if you have pet's & they are in your house then thats right, you got it, their hair will also contaminate the food. So wash & cook all of your food & understand that the FDA & USDA are the best in the world at what they do! ( Making our food's safe!) Imagine living in a third world country?

My Laboratory! Where else?

I believe many will because of 1.) our gag reflex 2.) Many usually see it by the time it will hit there mouth 3.) They can feel it in their mouth which makes them "search" with their tongue 4.) It might taste weird once the food is swallowed because it might have a different texture 5) Their tongue can catch it when the food is swallowed because of the tongue being raised to make it slide down. 6) lol any other reason other than my knowledge

How would we know?

duh.