Poppy, I know when they are ready to come out. I get a sick headache and feel pretty rotten. Then, when on the pot, they show up.
Two other types are starting to show up now. One is real black peanut shaped ones which I decided were intestinal flukes that have hung around for a really long time.
The other one is pure white and comes out when I urinate. The skin right below my eyes are puffy slightly. Which, of course, is a sign of kidney stress.