The fish don't build nests. They simply lay about 20,000 to 50,000 eggs per female and let the young care for themselves. Smelt prefer to eat other fish. And believe it or not, the adult smelts are known to eat young smelts. Parents actually are known to eat their own offspring.
Young smelt are often transparent.
You can see through them up until the point they've grown to at least two inches in length. Young smelt like to eat insects and small shrimp. Smelts are known as predators about not only their own kind but upon small trout and other types of fish, including minnows. If you're going to have a tank with smelt, be careful what other kinds of fish you want to maintain with them. Inc. Pagewise makes no representations about the content published on this site.