The Cybermats originated on Mondas during the earliest phases of Cyberman history, when most of the planet had not yet been converted. They were kept as pets. The Cyber-tombs on Telos had tunnels for the Cybermats to move from the tombs to the main control rooms. Cybermats were also seen on the surface of Telos. On GSO Arctic Drilling Station in 2010, most of the crew had been converted into Cyberslaves by the Cybermat's nanovirus. The Eleventh Doctor repelled the Cybermats with a specific frequency on a sonic amplifier device and found a cure for the nanovirus to treat Chisholm. In 2011, a group of Cybermen who had crashed on Earth centuries before were able to make their way to the surface. A Cybermat was used to drain electrical energy for the crashed Cybership so they could begin full Cyber Conversions. One was named "Bitey" by the Eleventh Doctor for its organic mouth. The Doctorreprogrammed it to drain power from the Cybership, but a Cyberman stepped on Bitey, destroying it. The Cybermats were used to guard the Cyberfactory when the Ninth Cyber Legion invaded London in 2012. The Cybermats were destroyed with the Cyberfactory. Cybermen from the 30th century who traveled back to 1940 also employed Cybermats and harvested humans to make more of them. The Cybermats appeared to have something to do with the conversion process. In 2503, a Cybermat smuggled itself aboard the Vanguard and began sabotaging its systems. Vol shot it, disabling its weapons, but the Cybermen reprogrammed it to take control of the crew's minds. The Master once forced the Graak to steal a disabled Cybermat.