Originally native to the arid southwest of North America, the resourceful house finch (Carpodocus mexicanus), is now found in every U.S. state. After nesting, the finches gather into sizable flocks — ours are particularly fond of hanging out in the Pineapple guava (Feijoa). They are attractive little birds with a pleasing sort of bebop jazzy song (performed by the male). You can listen to it at the Cornell Lab of Ornithology.