I have 8 chicks that will be 5 weeks old on friday. At what age do you worm chickens and how often? What do you use? Does DE work for worming? Should I use DE now in their sand box to help prevent mites and lice (they dont have any)! What about vaccinations? Are they really necessary? We got our chicks from a local feed store and they have been very healthy and are growing like weeds. I just want to make sure that when we put them out in the tractor, they have all the right things they need to stay healthy. Input anyone???