It occurs to me that the "you need to do some physical labor" part of that might be an effective parasite-repellent. All cooperative endeavors need some method

It occurs to me that the "you need to do some physical labor" part of that might be an effective parasite-repellent. All cooperative endeavors need some method of handling the occasional parasite, because otherwise they will tend to accumulate. If they have to do physical labor, they would, I'm guessing, tend to move on quickly.