Photo by Jan Hamrsky
  • Family: Freshwater Crustacean
  • Size: 5-9mm
  • Emergence: Available year round
  • Emergence Time: all day

Scuds and sowbugs are a two pronged insect in the Montana area. Both are found in abundance in many alpine lakes, as well as Georgetown Lake, and are a staple on the Missouri River, where we spend a lot of time in May and early June.

Photo by Jan Hamrsky

The difference between the two  is a scud is oval in shape while the sowbug has a flat profile. Both behave the same in the water, as both are basically freshwater shrimp. In Alpine lakes, the effective scuds are natural in color, ranging from dark gray to olive, as are the sowbugs. We prefer a natural color bead on our lake scuds. The Missouri River scuds all seem to work much better with a hot bead. It may be due to the massive amounts of food found in the Missouri- the hot bead allows fish to find them. We just know the hot bead can be critical on the Missouri. Scuds and Sowbugs live in the aquatic plants found in these bodies of water.

These bugs are a sign the water is very fertile and healthy, and are amongst a trout’s favorite food when they’re present. If you’re lake fishing, or heading to any tailwater in Montana, make sure to bring your scuds and sowbugs.

Additional Scud Resources