Pillagers spawnen ends and?

Have pillagers banner in the base in minecraft 1.14.2 they always spawn in the artificial forest where my friends and I can always farm wood can I prevent that? Nerves really.

Or should I just illuminate the forest as the very large open space I have?

I think you have such an effect that it always spawns it is shown as poisoning only that it means otherwise and infinite you should make / effect clear