Eggs
If an egg rises to the surface when placed in some water, it’s no longer edible. This occurs because gases accumulate inside an egg as it gets older, causing it to float.
One more curious thing about them — red spots
These are actually blood spots (or meat spots) caused by a ruptured blood vessel during the egg’s formation. The reasons may be the age of the hen and her diet, but the spots are no way a sign that the hen is unhealthy or has been mistreated in any way.