Hibernating cave myotis may form clusters. Uses temporary night roosts. Nursery colonies are in the hibernation cave or another cave. Occasionally other sites, such as bridges, are used. Males may be found in the maternity colony.
Optimal sites are relatively warm, with little human disturbance.
Feeds along riparian vegetation, over water, between patches of riparian vegetation, and to a lesser extent over open areas. Emerges soon after sunset, earlier if sky is overcast. A second peak of activity occurs shortly before sunrise. Juveniles and lactating females emerge later, and juveniles may have unimodal activity patterns. In Arizona, hibernation begins in September or October, females before males.