One of the top egg producers in the U.S. confirmed that a farm tested positive for cases of bird flu over the weekend, the company said in a statement Tuesday.

Indiana-based Rose Acre Farms, the second largest egg producer in the U.S., has confirmed fowl deaths from bird flu at its southern Indiana facility.

The humble egg, one of nature’s perfect foods, a self-packaged, relatively inexpensive source of protein that can serve as a lowly hangover remedy or help a souffle rise to heavenly heights, is also a great teacher. It’s helping Americans understand how a free-market economy works: When demand is high and supply is low, prices rise.