A Lively group

ORRINGTON – A lively group of Milford cub scouts recently visited the Fields Pond Audubon Center for a nature walk. They slowed down just long enough to glance at the number of little caddis fly houses littering the bottom of our pond. When their naturalist said that every tiny clump of twigs was actually a “log cabin” built by a tiny insect, they stopped all random movement and actually focused and observed closely.

“I see its arms moving!” one shouted. “There’s one hanging onto a leaf for a boat!” shouted another.

An intriguing creature is the caddis fly. These are in the larval stage of their life – underwater. They won’t fly in the air till next spring! And, they have the unusual habit of building, and then wearing their houses.

Camouflage and protection

If you have never seen them before, you might think it’s a little half-to-one inch-long clump of grass or sticks. But if you watch closely, the little clump of twigs is arranged, log cabin style, and it’s moving! In fact the caddis fly has built a small home that surrounds its soft body.

Legs and head stick out of the front of the cabin as the caddis goes about its business of hunting for food. The insect’s long abdomen is tucked inside the cabin of twigs or grass, protecting it from predators. All winter long the caddis fly will scour the pond, eating and growing and expanding its house as needed.

Occasionally this fall there has been a thin layer of ice covering the pond. This is a wondrous time to look at pond life. It’s like looking through a window. The surface of the water is perfectly still (since its frozen), and as clear as glass. The ice isn’t thick enough to stand on, so you must look from the dock or shore. One of the first things you’ll notice is the caddis flies. These remarkable little engineers crawl along the underside of the ice searching for food, offering us another view of their life.

Send sightings, comments, or questions to fieldspond@maineaudubon.org