I have a question about worming. My chickens are 16 weeks, 13 weeks, and 8 weeks. I understand to give them Valbazen or Safegaurd and I know I have to retreat 10 days after the first dose. But I also have read that they don't really need it till they are about 8-10 months. My question is that it has been raining a lot here. A couple weeks ago we got 7-8 inches of rain and now it's going to be raining off and on for the next 3-4 days. My chickens seem healthy. No odd poops or odd behavior. Just wondering if I should go ahead and start on my 16 week olds, then wait for the others to get to 16 weeks to do them, or if I should just wait till they are all old enough.