Discover nature this week with Missouri wrens. Wrens are among the smallest songbirds, yet they make their presence known in a big way. They are both loud and persistent singers. Birds use song, in part, to announce their breeding territories. House wrens aggressively defend their territories, often driving away much larger birds, and even mammals! Wrens are energetic brown birds, smaller than sparrows, with slender, slightly curved beaks. Wrens pose with their tails cocked in an upright