I would dust them also, just to be safe. I know it's impossible to keep those little wild birds away, but if there is a way to keep their food someplace out of reach (like in the coop?), do that also.
Ivermectin cattle drop on wormer will take care of roundworms, lungworms, a bunch of other worms, and lice/mites. If you're ok with using wormer, drop .25cc on their backs (make sure it gets to their skin) twice a year. That will take care of those little suckers for sure! If you do that, you don't have to dust.