Can you give earthworms as treats? I read on here that you shouldn't give earthworms as treats because they could get worms from them. If they are free ranging, aren't they going to eat worms anyway? We can't watch what they eat all the time.
I've heard that before about getting worms from them. I don't know how true that is but I won't argue it. You're right though, that if they're free-ranging they may well find and eat their own and there's nothing you can do about that. I wouldn't worry too much about it but personally I never feed worms to the birds for quite a different reason: I want as many earthworms in my soil as I can get - there is nothing better for improving the soil. Basically, the grubs/bugs that help me - earthworms, spiders etc. - I never feed off to the chooks. On the other hand, I garden organically so every day I pull pests off my vegies - aphids, grasshoppers, caterpillars, slugs - and those go right to the birds.
Chickens will definitely find worms as they scratch the ground...
Not sure what the source of your worms is, but I wouldn't feed worms to mine because earthworms are one of the intermediate hosts for some chicken parasites.
I got my chickens and went to the fridge where my husband had a styrofoam container of fish bait worms (night crawlers).... I fed to my chickens. Subsequently I noticed that my chickens developed worms. Now, there is no way of knowing for certain if they had worms when I picked them up or if they developed worms from the fishing worm that I fed them. Earth worms are definitely part of the infection cycle of some parasites.
Feeding meal worms to the chickens for treats seems much safer. Mealworms that are freeze-dried are readily available and seem unlikely to ever expose your flock to a parasite infestation.
Now, the store bought worms may be a better source of disease than the ones that the chicken finds in their foraging. You may have a preventative worming program set up for your chickens, or you may feed enough DE to feel that the risk is low, but you should be aware that there is a risk.
Unless you have them completely enclosed at all times, they are going to encounter something that could give them worms. I just worm mine once or twice a year and I think a lot of us do. Yes, they will encounter all sorts of potential hosts when they are outside the coop. Heck, even inside the coop they can get crickets or roaches or something that are also potential hosts to a parasite like roundworms.
Have a regular worming schedule and don't worry about it. That is my advice.