what is the difference between fertilized & unfertilized eggs

sorry to be so ignorant, but i have heard people say they don't like to eat fertilized eggs - why would this be the case?

It's a mental block.

If no one told them which was which, they'd not know the difference. Many eggs at a whole foods type store are indeed fertile. Proved by folks hatching them. The "spot" is soooo tiny that unless you are knowledgeable, you'd not likely even see it. Again, it is mostly a mental block.

some people say that fertile eggs have a stronger taste.

I think some people also don't want to eat fertile eggs because it feels like a waste to eat it instead of hatch it.

Who knows why people say the things they do. There is no taste or nutritional difference between a fertile egg and an infertile egg. Here is what they look like
To the untrained eye, one would never know the difference.

I think some people have it in there heads that with fertile eggs they are eating a chick.

Or, they've heard some horror story about cracking a partially-developed chick into a pan...

is there any way to tell besides cracking them open? we want to start hatching if possible... is there a way to tell by the hens behavior? eg. do they only brood when they are fertilized? does a rooster have to be at a certain age to fertilize?

sorry for all the questions... still new to this chicken business! love having them and love having the eggs! would def like to be more informed about some stuff tho!

if you have a rooster to every say 10 hens [depends of the breed] then a good guess is that all your eggs are fertile. the odd time one may not be, not a problem really, put the eggs under the broody hen, seperate her from the flock perferably in a quiet safe place with wheat and water, and wait 21 days. then you will know how many eggs are fertile, if the egg doesn't hatch, shake it gently and if it sloshes, throw it away. but give her 48 hrs to hatch out. some eggs take a little longer and some are a little shorter. as the chick develops iin the egg the egg seems to get heavier. no chick and it stays light. if you have tomany roosters per hen, the hens hide and then you may not have all fertile eggs. people are strange, we get a lot of people will only eat LARGE BROWN eggs. sometimes i ask if they eat the shell, not sure of the difference between brown and white calcium hummm..... smaller eggs are the tastiest. i like the pretty blue and green ones but never eat the shell, lol just eye candy .

Chances are pretty good that if you've eaten eggs throughout your life-you've eaten a fertile egg at least once. Most big chain places try and keep only hens, but when you have 20000+ birds, some roos slip through the cracks.

As everyone has told you, there is no difference. You would not notice. A fertilized egg does not contain an embryo until incubated. There's no little invisible baby that will be eaten. The egg is not overflowing with rooster ... genetic contributions.