Hackle is used to create surface area which helps the fly to float. It also gives the impression of insect legs.
The silhouette of this fly has proven very effective
Adult Caddis live significantly longer winged lives than mayflies and will spend up to two or three full weeks away from the water. When they’re finally ready to mate, males will gather near their home water to form a swarm. Females will join the swarm to have their eggs fertilized. Once the mating process has been successfully completed, females will deposit their eggs on the water’s surface, propagating the species.