Normally need worming at 6 months old or prior to first lay. We use Flubenvet at that age. I think 16 weeks is the earliest they can be wormed at using Flubenvet , but a 'breeder' I know used Harkers pidgeon worming tablets at 12 weeks. I will add that they were totally ineffective when we tried Harkers and we had to worm with Flubenvet in the end. Verm-X got better results.