Oak galls are abnormal growths that form on the leaves, stems, or roots of oak trees when certain insects, such as wasps, lay their eggs on the plant. The tree reacts to the presence of the eggs by producing a growth that provides protection and nourishment for the developing larvae. These galls can vary in size, shape, and color, depending on the species of insect and the type of oak tree. Once the larvae mature, they emerge from the galls, leaving behind a hollow structure. While oak galls are often considered a nuisance, they play a role in the ecosystem by supporting various insects and providing habitats. Additionally, some galls have been used in traditional medicine and dye production.