Those are liver flukes. The young ones are white and pink while the older ones are red and the "elderly" ones are almost black in color. This is because the blood in the liver stains the flukes bodies. The darker the color - the longer they have been in there.
Most all parasites will try to migrate, but the ascaris are notorious for speedy travel! This is why HUMAWORM contains 25 herbs - 10 of which are targeted to remove parasites from ALL parts of the body - all 10 do it in different ways all at the same time. The parasites have no where to hide.