Introduction to Bats

What is a Bat?

Bats are amazing animals, and an important part of our natural environment. 

Flying bat isolated on black background. The grey long-eared bat (Plecotus austriacus) is a fairly large European bat. It has distinctive ears, long and with a distinctive fold. It hunts above woodland, often by day, and mostly for moths.

Bats are Mammals

A long time ago, people used to think bats were birds without feathers.  But now we know that there is no such thing as a featherless bird.  We know that bats are MAMMALS, just like people.

Some of the things that tell us bats are mammals:

  • bats are warm blooded
  • Bats give birth to live young
  • bats nurse their babies with milk
  • bats have fur 

But bats are very special mammals.  

They are the only mammals that can fly (without an airplane!)  Flying squirrels are mammals too, but they don’t really fly.  They jump from high in a tree glide through the air like a kite.  Bats flap their wings and fly like a bird.

How long have bats been around for.

Ancient Ancestors

Scientists have found evidence that bats have existed for 50 million years.  Some scientists believe it may have been even longer.

When trying to understand how bats have lived,  scientists study living animals.  But no one was around 50 million years ago to study the beginnings of bat life.  Scientists use “fossils” (old bones) to try to learn about how bats evolved.

The earliest fossils of bats that we’ve found look very much like the skeletons of bats today.  This tells us that bats haven’t changed much over the years.

What kind of body does a bat have?

Where do bats sleep?

The bat cave!

The place where a bat sleeps is called its “roost”. Bats have a summer roost and a winter roost.

Bats hang UPSIDE DOWN from their roosts when they sleep.

Although some bats roost in groups of only one or two, for the most part bats are very sociable animals.  They usually sleep together in huge groups.

Some caves may be home to thousands of bats.  The largest bat colony in the world is in Bracken Cave, Texas.  During the summer, this cave is home to as many as 20 MILLION Mexican free-tailed bats.  That's a LOT of bats!
Caves aren't the only place that bats "hang out".  Bats also sleep in trees, mines, under bridges, in bushes and even in old buildings or barns.  Some tiny South American bats make tent-like shelters out of palm tree leaves.

Bats that might have typically lived in caves have begun to adapt to urban life by modifying their behaviour to live in man made structures in the city. The largest urban bat colony is under the Congress Avenue Bridge in Austin, Texas. The bridge is home to about 1.5 million Mexican free-tail bats. To put that in perspective, Austin is home to only a little over 1.5 million people -- there are nearly as many bats living under the bridge as there people living in the entire city!

What do you call a bat baby?

A baby bat is called a "pup"

Bat pups are tiny when born, but grow up fast.  Some species are flying and hunting on their own within a month of birth.

Bats, like people, usually only have one baby at a time although on occasion they’ll have twins.

Pups are born without hair — they look tiny, scrawny and pink.  They drink milk from their mothers like all mammals do.  They are born with strong legs and claws because they have to hang on to mom when she’s roosting and to the cave when she’s not there.  If the baby looses its grip and falls, it will die.

What's special about bat senses?

Bat senses

Bats smell, hear, taste, feel and see just like people do.  The term “blind as a bat” isn’t really accurate.  Bats have perfectly good eyes for seeing in the daylight.  The problem is, they do most of their hunting at night!

Instead of relying on their sense of sight for night-time vision, bats make rapid high-pitched squeaks called “ultrasounds”.  These sounds are too high for most people to hear.  If these sounds hit something, they bounce back — sort of like when you hear your echo in a mountain or a bathroom when you shout.  The bat hears the echo and can tell where the object is.  This is called “echolocation”. 

We all know that we shouldn’t talk with our mouths full — and this causes a certain amount of difficulty for some bats who eat while flying (they swoop and catch insects — eating them while they’re still in the air).  Although some bats make the squeaks needed for echolocation with their mouths, many send out sounds through their noses.  Bats that echolocate with their nose often have special flaps and folds of skin on their faces called “nose leaves”.  Scientists think that the nose leaves help the bats send the sounds in different directions.  The nose leaves give the bats a rather odd appearance!

Bats have the best hearing of all land mammals.  They often have huge ears compared to the rest of the body.

Below: Sparano pipistrelle 

Below: Common pipistrelle

Below: Noctule