An animal's eggs hatch through the heat generated by microbes in the soil and compost when they decompose organic matter, but these microbes (including bacteria) can also penetrate the eggshell and infect the embryo, which is naturally more than 20%
The eggshell of clump pheasant  is wrapped in a layer of nanometer calcium carbonate, which has stronger water resistance and resistance to bacterial invasion.
 However, in Australia, there is a bird called the clump pheasant, whose eggs are only 9% likely to be infected, and the researchers found that their eggshells contain lysozyme, which the researchers believe is likely to be a key factor in defending against bacterial invasion