Well, here goes. I usually worm once a yr. I read a study that said all chickens have worms but they are usually kept in check. I did notice some very pale combs and some worms in feces. So, I wazined my group when they were not laying well in the early winter, followed by ivemect. I would however do it different now. I would go the route of Valbazen. The wazine does not get rid of tape worms or gape worms and is very hard on the chickens. The val. works more slowly but takes a 24 day egg delay. I think this year I will val. my new chickens at 3 months. That way there will not be a wait on the eggs as they are not laying yet. Worm eggs in the soil or on the hens fluff when it comes to chicks can be a carrier. Bugs etc. Hens that do not have to fight a large worm load eat less, lay better and generally are healthier. Gloria Jean