Spring time is worm season. When stream flows are up, aquatic worms are stirred into the current stream. Even the most picky and selective trout can’t resist a worm imitation at these times. The addition of a tungsten bead to a san juan worm, gives the traditional dressing weight. San Juan worms tied without weight have a nice neutral buoyancy. The tungsten bead helps get the fly down when you need it most- during the higher flows that dislodge aquatic worms.