A tiny, long-tailed, fluffy gray ball of a bird. Distinctly drab brownish-gray with a stubby dark bill. Multiple populations differ slightly: eye color ranges from dark to pale, and some have black cheeks. Constantly in motion; active, twittering flocks move quickly through bushes and trees. Listen for their high-pitched, scratchy calls.

The bushtit's name (Psaltriparus minimus) has the same origin as the titmouse's. The scientific name for Bushtit is Psaltriparus minimus and the second half of Psaltriparus, “parus,” is Latin for titmouse. And the “tit” in titmouse comes from Old Icelandic “titr” meaning something small.