The eroding stream banks here offer nesting habitat for northern rough-winged swallows. Please be aware that the banks are very unstable. This accelerated erosion, as well as area land use practices, impact the quality of Catoctin Creek. Volunteers assess the quality of the creek and the surrounding environment three times a year and provide the data to appropriate state agencies. Bottom-dwelling aquatic insects such as mayfly, caddisfly and stonefly larvae are biological indicators of good water quality.