Rats are typically referred to in collective nouns such as a colony, a swarm, a pack, a mischief, a plague, a horde, and a rabble. A colony is a large group of rats living together, while a pack is a small group of rats living together. A swarm and a plague is a large group of rats running around.
The etymology of the collective nouns for rats such as a colony is derived from the Latin word colonia, which means a group of people living together. This term was later used to describe a group of animals living together, such as a colony of rats. The term swarm is derived from the Old English word swerian, which means to move in a large group. This term was used to describe a large group of animals, such as a swarm of rats.