Just look at the size of those talons.
"Strong feet and claws help them climb the sides of trees as they probe for food in crevices, cracks and under bark with their long curved bills. A variety of spiders and insects are eaten but ants are a particular delicacy. The White-throated Treecreeper flies to the base of a tree and begins to work up the side of the trunk, spiralling as it ascends. It moves upwards with a peculiar shuffling motion, always leading with the same foot. Unlike some other bark-feeding birds, such as sittellas, treecreepers cannot climb down head first. All their vertical; movements are directed upwards, although they do have the ability to walk along the undersides of horizontal branches, hanging upside down. This species may opportunistically take nectar from flowers but unlike other Australian treecreepers which regularly forage on the ground, it rarely descends from the trees."*
*Boles, Walter (1986). Birds of the Australian Rainforests. The Currawong Press, p.127.