Black-capped sings a two note song while Carolina sings a four note song. Hybrids sing a three note song. Mixed deciduous-coniferous forests, woodland edges, clearings, fields, thickets, orchards, suburbs. Often seen foraging in low branches of trees. Will come to feeders.
Mating system is monogamous.
Require 10- 14 days to excavate and line cavity. Both sexes help with nest construction. Both sexes incubate. Incubation takes 11-13 days. Young leave the nest after 14-18 days.