Dont all rush !!
We're verylaid back here
This is my advice:
You have to assess the risks.
Many birds, intensivly farmed on the same land for years, particularly free range = high risk of worms.
Few birds, clean land, even free range = low risk of worms.
Having said that they can pick up gut worms from wild birds and gape worm from birds, worms, slugs and snails. For the owner new to hen keeping it is a good idea to worm regularly (I recomend flubenvet every 6 months) but for an experienced keeper who is confident enough to spot the signs when worm burdens get too high, worming as and when symptoms may show is fine.