Carolina wren

http://www.50states.com/bird/carwren.htm droop tail while sing

"When satiated with food, or fatigued with these multiplied exertions, the little fellow stops, droops its tail, and sings with great energy a short ditty something resembling the words come-to-me, come-to-me, repeated several times in quick succession, so loud, and yet so mellow, that it is always agreeable to listen to them. During spring, these notes are heard from all parts of the plantations, the damp woods, the swamps, the sides of creeks and rivers, as well as from the barns, the stables and the piles of wood, within a few yards of the house. I frequently heard these Wrens singing from the roof of an abandoned flat-boat, fastened to the shore, a small distance below the city of New Orleans."

http://faculty.maryvillecollege.edu/crain/ornithology/Anne%20Marie/great_carolina_wren.htm

Behavior

The flight pattern of the Carolina wren is on of short wing strokes.  The tail is usually held erect, and movements are rapid and jerking, almost mouse-like.  At times, an individual may perch with the tail drooped and sing a full song resembling a full, yet mellow "come-to-me, come-to-me" phrase.  This is in contrast to the firmer "chirr-up," which may be heard throughout foraging.  Songs may be heard throughout the day, even after sunset.  The commonly heard "tea-kettle, tea-kettle, tea-kettle" phrase may be heard below.  Males call year round, although winter calls are much less extravagant than are the songs of the mating season.          

The general habitat includes areas of marsh or successional scrub vegetation, and are often located near bodies of water.  A very resourceful bird, Carolina wrens will extend habitat to barns, woodpiles, and suburban areas.