Ants

Ants were tiny insects that form large communal colonies under the rule of a single queen. Though Tolkien doesn't mention them directly, we can deduce their presence in Middle-earth from the fact that Merry discusses them briefly with Pippin on one occasion. Tolkien uses their qualities freely in similes throughout The Lord of the Rings, especially in reference to the Orcs of Mordor, whose military organisation and aggression are referred to several times as being ant-like. At one point Sauron is compared to an ant queen, with his Orcs acting as soldiers and workers just as the queen's in her colony.