My vet told me that many animals can tolerate normal worms, but that an animal that is immune-compromised will have a tougher time fighting off worms. If one sees a lot of poultry diseases in the flock, there may be a bigger need to deworm. Having a fecal test done occasionally from several...
That is probably just something that an individual chicken is doing--I 've had a couple that have done that, and I don't think it has anything to do with worms. However, you can use SafeGuard equine paste or goat wormer to worm your dhickens.