As a result, marshes popular with wrens often contain many completed and partially finished nests. Most of these nests are empty, though, and this may be one way Marsh Wrens protect their young. Predators looking for eggs or young birds would have to check out lots of nests, and all that effort may not be worthwhile.
Typically, the wrens lay five or six eggs which are dull brown with dark brown spots. The female incubates the eggs for 13-16 days, and the young fledge between 11-16 days after hatching. Marsh Wrens usually hatch two broods per season.