The wrens build their nests in the tips of living Spartina. The nests are made out of dead Spartina. They are not open, but are covered, so the nest looks like a ball of dead grass. There is a hole on the side that the birds can enter. The nests are built above the level of high tide, but a big storm or hurricane can flood the nests and drown the eggs or young birds. The males build several nests, but the female chooses only one in which to lay her eggs. The other dummy nests might distract predators from the real nest.