Variable Colony Sizes
Bat colony size depends on species and location. Some colonies include only a few individuals, while others number in the hundreds, thousands, or even millions.
Big brown bats may form colonies of dozens to several hundred. Mexican free-tailed bats can exceed a million. Vampire bats usually range from 20 to 100, pallid bats from 10 to 50, and hoary bats are mostly solitary except in winter.