Mice

Mice serve as test subjects in the molecular dissemination experiments led by Froyn and his scientific team on behalf of the Daleks' allies. Confined to a glass capsule, they endure transposition across vast distances to the planet Mira's inhospitable swamp. Their complete survival—alive and unharmed—establishes proof of concept for the technology, directly influencing decisions to apply it to human subjects like the Doctor and companions. As standard lab animals, they embody the raw material of high-stakes research into interstellar matter transfer.