Wrens are a family of mostly small, brown, passerine birds in the (mainly) New World family Troglodytidae. The family includes 88 species divided into 19 genera. Only the Eurasian wren occurs in the Old World, where in Anglophone regions, it is commonly known simply as the "wren", as it is the originator of the name. The name wren has been applied to other, unrelated birds, particularly the New Zealand wrens (Acanthisittidae) and the Australian wrens (Maluridae).

The family name Troglodytidae is derived from troglodyte, which means "cave-dweller", and the wrens get their scientific name from the tendency of some species to forage in dark crevices.

Most wrens are small and rather inconspicuous, except for their loud and often complex songs. Notable exceptions are the relatively large members of the genus Campylorhynchus, which can be quite bold in their behavior. Wrens have short wings that are barred in most species, and they often hold their tails upright. As far as is known, wrens are primarily insectivorous, eating insects, spiders, and other small arthropods, but many species also eat vegetable matter and some take small frogs and lizards and many more amphibians.

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