A Blue-Gray Gnatcatcher. The “little mockingbird.” May 27, 2020 A Blue-Gray Gnatcatcher. The “little mockingbird.” Gnats aren’t a significant part of a Blue-gray Gnatcatcher's diet. The Blue-gray Gnatcatcher produces high, buzzy, mewing notes. ← It seems as if the lilacs leave the minute they arrive.Napping with eyes wide open. →