Primary roosts are generally larger than alternate roosts, but both show variability. Females typically use large roost trees averaging 10.8 to 25.7 inches (27.4 to 65.3 cm) as maternity roosts. Males are more flexible, roosting in trees as small as 3 inches (8 cm) dbh. In a review, Indiana bats required tree roosts greater than 8 inches (22 cm) dbh, while roosts of 12 inches (30 cm) dbh or larger were preferred. The heights of roost trees vary, but they tend to be tall, with average heights ranging from 62.7 to 100 feet (19–30 m). The heights of the actual roosting sites are variable, as well, ranging from 4.6 to 59 feet (1.5–18 m).