A proper diet for pet snakes typically includes frozen-thawed rodents such as mice or rats. The size of the prey should be appropriate for the size of the snake. It's important to ensure that the prey item is properly thawed before feeding to the snake to avoid any health issues. Additionally, some snake species may also benefit from occasional variety in their diet, such as chicks, quail, or fish. Always consult with a veterinarian or a reptile specialist for specific dietary recommendations based on the species of snake you have.