Which of the following activities would be considered illegal hunting?

Shooting a deer without a license is considered illegal hunting because hunting regulations are established to manage wildlife populations and ensure the safety of hunters and the public. A valid hunting license signifies that the individual has undergone the necessary training and understands the laws and regulations governing hunting in that area. Engaging in hunting activities without a license not only disregards these regulations but can also lead to penalties, including fines or loss of hunting privileges.

In contrast, the other activities listed, such as deer hunting with a valid license, wearing an orange vest for visibility, and hunting during established open seasons, are all compliant with hunting regulations and promote safe and responsible hunting practices.