In terms of ecology, they would be called a population.
Population
Population
Population
P-o-p-u-l-a-t-i-o-n
Population
A group of mice are called a mischief or nest. A family is called a horde. The male is called a Buck and the female a Doe.A group of mice is commonly referred to as a family, and also as a horde, a mischief, or simply, and most frequently, a nest of mice.Other collective nouns describing mice include a colonyand a harvest. The former is self-explanatory; the latter from the fact mice and other rodents nest in the dry stubble of wheat and other cereal plants following the harvest.A group of baby mice is called a litter.Some might refer to mice, when they are regarded as a pest, as a plague, but this isn't a group (collective) noun as such, it simply illustrates the fact the creatures are a nuisance, as in a plague of cockroaches.
A population.
A community.
its a population
population
population
Nation-state