Eggs sink in water but rotten when opened

[Happywoman]

We always test our eggs by floating them. They sink, they're good. The last few days we've found this isn't always true.
The eggs are older, have not been washed. We tested them in water and they sank, but when we cracked them to cook, the entire inside was black and smelled terrible. There was also one that sank, but when cracked open smelled like rotten milk. Weird. We've always been told that when an egg sinks to the bottom, that means they are good to eat. Anybody have any ideas on what could have caused this? Not all the eggs were bad, just a few.

 

[missnu01]

If the eggs were somewhere where they could have taken in a good bit of water they will sink and be rotten..high moisture can also speed the process of spoiling, so where were the eggs? Could they have absorbed a large amount of water? Sitting in a puddle of some sort or anything like that?

 

[Happywoman]

The eggs were sitting on a table in the house, so I don't think they could have gotten much moisture at all. Any other ideas?

 

[Chickenjocky]

The loss of moisture causes the egg to float. As eggs get older they loose more moisture and eventually float. The float test is an indication of age, not edibility. Sounds like the eggs were attacked by bacteria and rotted.