Pallas’ Mastiff Bat or Velvety Freetailed Bat (Molossus molossus )
The body and head of this bat is together 5 to 10 cm (2-4 inches). The animal weighs 10 to 30 grams (0.4-1 ounce). One of the most obvious characteristics is the tail. It extends beyond the edge of the tail membrane. Also, it can be quite long, ranging from 2 to 7 cm (1-3 inches). It is because of bats like this one that people find a resemblance between mice and bats.
These bats can rest horizontally. They do not hang, but clutch to the wall with their feet and wing claws. If disturbed, they tend to scurry to a safer place instead of flying away.
These bats can be frequently found in roofs, attics and in bat houses. They leave their resting place early in the evening, often before sunset. Then they start catching insects, the only item present in their diet.
This kind of bat can be found from Mexico to Paraguay and in the West Indies.
Sometimes the presence of these bats under a roof may bother the human occupants. The worst thing to do is to fumigate. This will cause a lot of dead bats, followed by a terrible smell of decomposing bats. Much better is to contact a specialist.