Caddisfly larva (case-bearing caddisfly)

Freshwater streams, ponds, and lake margins, especially among aquatic vegetation and leaf litter.

Larvae graze on algae, scrape biofilm, or shred dead leaves; some species prey on small aquatic organisms. The pictured larva appears to be a plant- or leaf-material feeder.

The larva constructs and carries a portable case from plant fragments, sand, or pebbles, adding material as it grows. It pupates underwater, and adults emerge as short-lived, moth-like fliers attracted to lights.

Harmless to people and pets. Caddisfly larvae help break down organic matter and are important food for fish; their presence often indicates relatively healthy freshwater.