Colors range from gray to olive, tan and orange in scuds and mottled gray to pale olive gray in sowbugs. Lighter, brighter colors imitate the soft shell condition. Scuds resemble shrimp. Like shrimp, their legs extend down from the body. Their climbing legs are at thorax.
Scuds are very nimble as they dart and climb among the aquatic plants and other structure.
In ponds they should be fished with short twitches and jerks near the bottom. In streams they should be weighted so they drift along the streambed. Tan scud patterns best represent the soft-shell, or most vulnerable, stage. Olive is an intermediate color, and gray scuds have hard, fully developed shells. Scuds are also popular trout food, so there are many scud patterns available.