Fathead minnows aren't a fish you will catch with a rod and reel. They are generally kept as forage for your other fish. Stocked alongside your bluegill and redear, they give a brand-new pond an instant food source that jump-starts the growth of everything above them.
In a new pond, your gamefish need something to eat right away. Fatheads reproduce quickly and provide that early protein while your bluegill are still getting established as the main forage base.
They are meant to be eaten. Once bass go in, they steadily crop the minnows down, and in most ponds the fatheads eventually disappear as the bluegill take over. That is expected, and a sign the food chain is working.
Fatheads go in with the first, forage-focused stocking. They are sold by the pound rather than by the fish, and 5-10 pounds per acre gives the pond a strong early boost.
In subsequent years, fathead minnows can be stocked as a quick supplement for your other fish, but they will generally be eaten faster than they can reproduce.