A Bad Egg

I wanted eggs for dinner.  So I went to the fridge, pulled out the carton, and found more than enough eggs for a nice meal. 

But, egads!  I had no idea how old they were.  You see, sometimes to save space I'll consolidate old eggs and new eggs into the same carton.  I always forget which ones are which.  Should I risk it?  Dare I play the salmonella game?

I knew there must be an easier way than gastroenteritis to find out if the eggs were still good.