I have 5 hens who are 6 months old now. First question. How old should they be before worming? Second question. What is the best way to worm when you only have 5 birds? Last year I had two birds and the vet gave me a liquid medacine to give with a dropper into their mouths. She said it was the best way with only two birds to treat. Is it still the best way with 5 birds?