They are found both at forest edges and deep within forests. They are also common in rural and suburban areas containing scattered trees, such as old fields, thickets, and parks. Their diet consists of insects, caterpillars, snails, and spiders. In the winter, they eat the berries and seeds that they hid in the crevices of bark and under leaves. This behavior is called caching, and Black-capped Chickadees can remember the location of the stored food for up to a month after they hid it.
Most birds establish pair bonds in the late fall when winter flocks form.
Nevertheless, some birds die during the winter, and many birds must find new mates in the spring. Pairs establish and defend a territory, remaining on or near their territory for the rest of their lives. The onset of breeding, however, can be influenced by factors such as weather, food supply, and the condition of the breeding female. Black-capped Chickadees often nest in cavities they excavate themselves. They also nest in natural cavities, abandoned woodpecker holes, and nest boxes.