During the summer, the tricolored bat will roost in tree foliage or buildings, with females alone or in maternity colonies of up to thirty individuals.[1][2] Trees used for this purpose include oak, maple, the eastern cottonwood, and American tulip tree.[16] Males are solitary and do not form colonies.[15] In Nova Scotia, researchers discovered nearly one hundred roosts of this species, finding that all sampled individuals were roosting not in tree foliage, but rather in a species of beard lichen, Usnea trichodea. This was thought to be the first documentation of a bat using beard lichen as a roosting substrate. It was speculated that the tricolored bat may use the lichen to ward off parasites.