One way to find a black ant nest is to look for where the ants are coming from. If you see a line of ants marching into your home, follow them back to their nest. Another way to find a black ant nest is to look for small piles of dirt or sand near where you’ve seen ants. This is where the ants have excavated their nests. If you can’t find the nest, you can also try using a store-bought ant bait and following the directions on the package. The bait will attract the ants and they will take it back to their nest, which will help you find it.