Pewees eat flies, beetles, small wasps, and moths. They also consume elderberries, blackberries, and fruits of dogwood and pokeweed. Males defend breeding territories of two to six acres. The three eggs are incubated by the female and hatch after 12 or13 days. Both parents feed the young, which make their first flights at 14 to 18 days.
Blue jays are major predators, taking both eggs and young.
Most perching birds stop singing regularly in late summer, but male wood-pewees keep up their chanting until the autumn migration. The species departs from Penn's Woods in August and September, with a few individuals hanging on until October. Wood-pewees winter in the tropics from Panama to Bolivia, in shrubby woods and along forest edges. They spend much of the day hunting from a perch. When sitting, they occasionally flip their tails up and down.