Wikipedia
Aegithalidae
The bushtits or long-tailed tits, Aegithalidae, are a family of small, drab passerine birds with moderately long tails. The family contains 11 species in four genera, all but one of which are found in Eurasia. Bushtits are active birds, moving almost constantly while they forage for insects in shrubs and trees. During non-breeding season, birds live in flocks of up to 50 individuals. Several bushtit species display cooperative breeding behavior, also called helpers at the nest.