The Doctor has encountered many strange insectoid life forms throughout his travels in time and space. But perhaps strangest of all were the woodlice-like Tractators that he encountered on the planet Frontios in the far future. The Tractators had powers over gravity and could effectively “use the Force” (Star Wars style). They were led by the Gravis, who was an intelligent being that wanted the Fifth Doctor’s TARDIS. The disgusting Tractators were parasites and they wanted to travel from planet to planet, to breed and conquer. However, the Tractators were not the only giant woodlice that the Doctor has encountered in Doctor Who. The Twelfth Doctor also encountered some giant woodlice called Dryads in a haunted house in Knock Knock.

Frontios

★★★☆☆

TX: 26/01/1984 – 03/02/1984

Written by Christopher H Bidmead   Directed by Ron Jones

The TARDIS is dragged down to the planet Frontios in the far future by an unknown gravitational pull. One of the last surviving human colonies is struggling to survive on Frontios, as the encampments are bombarded by meteors and other debris. During one strike, the TARDIS is apparently destroyed, leaving the Fifth Doctor, Tegan and Turlough stranded on Frontios. The Plantagenet who leads the people of Frontios is considered weak by his subordinates, including Security Chief Brazen. The Plantagenet assumed the position after his father, Captain Revere was sucked into the ground. This is the same fate that awaits many of the humans on Frontios. Under the ground is a network of subterranean tunnels which have been dug by an intelligent woodlice species called the Tractators. A traumatised Turlough recognises the Tractators because they invaded his home planet a long time ago. The Tractators have powers over gravity and they have been dragging humans down through the Earth so that their animated corpses can be used to drive the Tractators’ machinery. They are also responsible for the regular bombardment on the planet’s surface. The Doctor, Norna and her father Mr Range confront the leader of the Tractators, the Gravis. The Gravis wants the Doctor’s TARDIS, the fragments of which have been scattered throughout Frontios. The Doctor tricks the Gravis into using its powers over gravity to pull the missing TARDIS components together, rebuilding the ship. The Gravis collapses and whilst dormant, the Doctor later drops it off on the barren planet of Kolkokron. The Doctor gives Plantagenet the TARDIS hat stand as a farewell token and asks that his own involvement in the situation should not be mentioned to anyone, especially the Time Lords. Once the TARDIS has left Frontios, its engines start making a concerning noise. The Doctor appears to be helpless as the ship is being pulled down a Dalek Time Corridor back to Earth. This story leads directly into the events of Resurrection of the Daleks.

Knock Knock

★★★★★

TX: 06/05/2017

Written by Mike Bartlett   Directed by Bill Anderson

Bill Potts and her university student friends are looking for a new flat to rent together. After having no luck, a mysterious landlord offers them a lease at his large, creepy old house. As the students settle in, the Twelfth Doctor arrives to help Bill move her stuff in too. The Doctor meets the Landlord who he is immediately suspicious of. The Doctor secretly sticks around after dark to investigate the house. One by one, Bill’s friends are sucked into the wooden walls of the house or are devoured by giant woodlice called Dryads (which are sensitive to sound) that scuttle around in formation. The Landlord says that they are providing sustenance for the Dryads to keep his daughter Eliza alive in the forbidden tower. The Doctor and Bill make it to the house tower, where they discover that Eliza is now completely made of wood. The Doctor deduces that the Landlord is actually Eliza’s son, a long forgotten memory. As a boy, the Landlord had brought his terminally-ill mother some dormant Dryads that he found, unaware of their power. When the Dryads heard a high-pitched sound from Eliza’s music box, they awoke and started turning Eliza into wood to counteract her illness. Since then, the Landlord has controlled the Dryads to keep Eliza in good health whilst signing on new tenants to become the Dryads’ source of nourishment. Eliza is able to control the Dryads, so she takes the Landlord into a hug, over his objections, and thanks the Doctor before the Dryads consume them, whilst also reconstituting all of Bill’s friends. The group escapes the house moments before it collapses in on itself. Back at St Luke’s University, Bristol, the Doctor offers to take over watch of the vault from Nardole. Piano music plays from within as the Doctor enters to have dinner with the unknown prisoner inside.