Heritage Acres Wild Bird Food Nyjer seed bird feed is a favourite of American Gold Finches and is ideal for attracting all kinds of finches. High in fat and protein, the mix is re-cleaned to remove contaminants and pesticides. It is also nutritionally balanced with a fortification of vitamins and minerals. The small black Nyjer seed is sterilized and will not grow. Clean feeders monthly to avoid build-up and prevent mold growth.