Why do eggs smell?

The smell of eggs is caused by the release of sulfur compounds, such as hydrogen sulfide and dimethyl sulfide, which are produced by bacteria that are present on the eggshell. These bacteria can enter the egg through small pores in the shell, and once inside, they can multiply and produce these compounds. The smell is often more noticeable in older eggs, as the bacteria have had more time to grow. Additionally, eggs that are cracked or have damaged shells are more likely to develop an unpleasant odor due to the increased amount of bacteria that can enter the egg. The smell of eggs can also be affected by the type of food that the hen has eaten, as certain feeds can lead to the production of different sulfur compounds.