A cockroach was an insect native to Earth. Mexico was particularly full of cockroaches — "more than you could have possibly imagined." (PROSE: The Left-Handed Hummingbird) It was said of cockroaches that, where there's one, there's a hundred. (PROSE: Timewyrm: Genesys)
The sanatorium at Glenwood Springs, Colorado was infested with cockroaches; Doc Holliday would pass the time shooting at them. (PROSE: The Gunfighters)
According to Sgt John Benton, the Blatherians resembled giant cockroaches. (AUDIO: Council of War)
In 1982, a nuclear bunker in England was attacked by giant cockroaches. (AUDIO: Day of the Cockroach)
The Eighth Doctor once compared the Daleks to cockroaches: "no matter how many you kill, there always seem to be more." (PROSE: Legacy of the Daleks)
Cockroaches were believed to be able to survive a nuclear war. The Eighth Doctor had been to planets where that had happened. (PROSE: The Gallifrey Chronicles)
Cockroaches were still around in Bernice Summerfield's native time. (PROSE: Birthright)
In 2593, Miss Diane Schirf, a passenger on the Titanian Queen, died when she choked on a swarm of cockroaches that attempted to burrow down her throat. (PROSE: Ship of Fools)
An Earth-like planet was home to large cockroach-like creatures. The sons of Grekk, who also lived there, viewed them and all the other intelligent life forms on the planet as vermin, and had vowed to exterminate them all. One of the cockroaches was held prisoner in the Pit, where he helped the First Doctor engineer an escape, and later restrained Deemon. (PROSE: The Sons of Grekk)
Raj Kahnu created mechanical suits that resembled cockroaches on Miasimia Goria. (AUDIO: Planet of the Rani)