a mischief of mice A nest or pack of mice or rats. ConfidencehighAttestationwiktionary-attestedAlso used forrats 2 sourcesWiktionary - mischiefWiktionary - Appendix:English collective nouns
a colony of mice Fanciful / unverified ConfidencelowAttestationwikipedia-uncitedAlso used forants, badgers, bats, beavers, bees, beetles, penguins, chinchillas, mustelids, rats +2 more 1 sourceWikipedia - List of animal names
a nest of mice Fanciful / unverified ConfidencelowAttestationwikipedia-uncitedAlso used forants, bees, hornets, pheasants, rabbits, snakes, termites, wasps 1 sourceWikipedia - List of animal names