Hawaiʻi creeper is able to climb up and down trees. It uses its short, sharp beak to probe bark for insects residing underneath. If available, it will sip nectar from koa ("Acacia koa") or ōhia lehua ("Metrosideros polymorpha"). The breeding season of the Hawaii creeper lasts from April to July, during which female birds lay one to three eggs. Nests are hidden in a tree cavity or built on a high branch in either a koa ("Acacia koa") or a ōhia lehua ("Metrosideros polymorpha"). Eggs hatch after around thirteen days. The Hawaii creeper was put on the endangered species list in 1975;
Acacia koa a diameter of . Flowering may be seasonal or year round depending on the location. Fruit production occurs when a koa tree is between 5 and 30 years old. The fruit are legumes, also called pods, with a length of and a width of . Each pod contains an average of 12 seeds. The long, wide seeds are flattened ellipsoids and range from dark brown to black in color. The pods are mature and ready for propagation after turning from green to brown or black. Seeds are covered with a hard seed coat, and this allows them to remain dormant