Rarely use buildings, occur as solitary family groups. Probably highly migratory. Present in San Francisco area from Sep to May but absent in summer, yet in Yolo County, absent in winter and present in Feb and Mar. Males may spend summer and falls apart from females. Peak activity 1-2 hr after sunset. Often feed under street lights.
Food includes beetles, bugs, ants and moths.
Known from Pinnacles and Hastings. Luxuriant, thick fur. A very strong flier, found over all of North America. This is the only bat to have reached Hawaii. Quentin Tomich, after many years collecting museum specimens of plants and animals from Hastings, moved to Hawaii where he collected many of the specimens there used to describe that taxonomic group of Hoary bats.