Barklice

Trunks and branches of smooth-barked trees such as oak, maple, and beech, particularly where lichen and algae are present.

They feed on fungi, algae, lichen, and organic debris found on tree bark. They do not eat the wood or the leaves of the tree.

Often called "tree cattle" because they move together in large, organized herds throughout their nymphal stages. They aggregate for protection and scatter when disturbed. They undergo simple metamorphosis.

They are completely harmless to humans, pets, and the trees they inhabit. They provide the benefit of cleaning the tree's bark by consuming algae and fungi.