The Family Molossidae, also known as the Free-tailed bats, comprise over 100 species of bats that are found worldwide. These bats have distinctive tails that extend beyond the edge of their tail membranes, hence the name "free-tailed". The Molossidae family is often referred to as the mastiff bats, bulldog bats, or dog-faced bats. This is because their faces are wide, with a short snout and prominent jaws. They also have a muscular build, much like a mastiff or bulldog. Molossidae bats are typically highly social and roost in large groups, often in man-made structures such as buildings or bridges.