They forage slowly on tree trunks and branches by poking their bill into pine cones. These birds also find food by searching for it on the ground. These birds mainly eat insects, seeds and berries.
Their nests are deep, open cups, which are placed near the end of a tree branch. Pine warblers prefer to nest in pine trees, hence their names. Three to five blotched white eggs are laid.
Ruby-crowned Kinglets forage actively in trees or shrubs, mainly eating small insects and spiders, some berries and tree sap. They may hover over a branch while feeding and sometimes fly out to catch insects in flight. The red crest is raised when agitated or in display. Often, they perform a “broken-wing” act to draw predators away from their nest, which they will defend fearlessly, mobbing the intruder which may be a cat, squirrel, or human.