Vrill

The Vrill are a sapient, non-spacefaring, hive-based insectoid species from a world just outside the Milky Way Galaxy.

Biology
The Vrill are insectoids with wings and clawed appendages, and build giant labyrinthine communal nests underground. They have no vocal cords, and communicate by producing scents.

The Vrill are divided into several castes, including workers, warriors, watchers, healers, and drones. Watchers are about the size of a cat, while workers are as large as an automobile. Drones are all male. Workers are all female and develop from fertilized eggs. Unfertilized eggs give birth to warriors, which are neuter. A female Authority (equivalent to the queen in Earth's eusocial insects) rules the colony and is responsible for laying the eggs and controlling which eggs will be fertilized, as well as producing the nutrients that cause an egg to develop into a new Authority if needed.

Vrill eggs are kept in water rich in nutrients, and their shells are extraordinarily strong, requiring the Vrill's superhuman strength to break. They are born full-sized, capable of communicating, fully aware of their social functions and ready to start labouring.

Culture and society
Individual Vrill have no names, being identified only by their social function. The concept of deception seems to be entirely alien to them, thus making them appear gullible.

Appearances

 * Big Finish Doctor Who audio stories, Survival of the Fittest (2010)