We've had chickens for almost 10 years. I get new ones every other fall or so, since we're selling eggs. We've lost many over the years to predators (mostly opossums and hawks) and one whole flock to marek's (now we get them vaccinated). They're completely free range and a lot of them are roosting in the barn. There completely a mess, I don't know which ones are laying any more. I'm sure they need worming. Basically, I don't feel like I'm taking very good care of them. Probably need to get rid of the old ones (all except for Lady, the java, and she's 9 years old!), but don't know how I'd do it. So question is - how do I worm them when they're all over the place? They do come to feed at the same time every am. Wormer in the feed?