 However, they do not eat plant roots; they only cause damage indirectly, as they eat earthworms and other small invertebrates in the soil.However, while moles may be viewed as pests, they do provide many positive contributions to the soil, gardens, and the ecosystem, including soil aeration, feeding on slugs and other small creatures that "do" eat plant roots, and providing prey for other wildlife.In Middle English, moles were known as "moldwarp".