Why is the blow to the groin so painful?

A blow to the groin is painful in men. It is related to the genitals. The genitals play a very important role for any living organism that reproduces sexually. In humans, the genitals have a large number of nerve clusters. There are many more nerves concentrated there than in other organs and tissues. Therefore, a blow to the groin is much more painful than a blow to the stomach, shoulder or other part of the body. This feature is associated with the importance of this organ for the survival of the species. Therefore, animals must avoid damaging the reproductive system.