Text Leveling System

Bats

RDQ:	936	Max Word/Sent	25	Total Words	1163		Diff Words	471
Lex	730	Ave Word/.Sent	10	Hi Freq occurs	695	59.8%	Hi freq	178	37.8%
AR	3.5	Long Sentences	1.9	Low Freq occurs	61	5.2%	Low freq	49	10.4%

Bats dive, swoop and swerve through the dark night sky. These creatures are nocturnal,
meaning they are awake at night and sleep during the day. Most people have never seen
a bat.]]
Bats have played an important part in stories. Many people have thought bats were evil
spirits. Others have thought they were friends of ghosts and witches.]]
Because many unkind things have been said about bats, some people still think they are
scary. Actually, bats are shy and gentle animals.]]
Bats are mammals, as are dogs, cats and humans. All mammals are warm-blooded
animals, and their babies are born alive instead of being hatched from eggs. Bats are the only
mammals that can fly.]]
Bats have been around for a long time. The oldest bat fossil found is about 50 million
years old. These prehistoric bats look a lot like today's bats.
All bats have the same basic characteristics, including large wings, small bodies and light-
weight bones.]]
Bat wings are different from the wings of insects or birds. A bat's wing has long arm bones
with very long finger bones. A thin skin, called a membrane stretches between the bones.
The thumb ends with a claw.]]
The membrane connects the wing bones to a bat's body and legs. A bat can move each
finger separately to change the shape of its wings. This helps it change its speed and
direction quickly.]]
Some bats can fly as fast as 15 miles (24 km) an hour and as high as 10,000 feet (3,050 m).]]
When a bat lands, it flips upside down and hangs by its toe claws. It uses these claws to
move around.]]
Bats choose many kinds of dark nooks and crannies to live in. These places are called
roosts. Many bats live together in caves, attics, barns or tall trees. In places where it gets
cold in the winter, some kinds of bats migrate to warmer climates; others use their roosts
to hibernate until spring.]]
Just before hibernating begins, bats eat lots of food to live on during the long winter
months. Their heartbeats slow down, and their body temperature drops.]]
Bats live on every continent except Antarctica. Most of them live in hot climates where
there are many insects, fruits and flowers to feed on.]]
There are about 1000 different kinds of bats. The smallest is the Kitti's hog-nosed bat. Its
wingspan is five inches (13 cm) and it weighs only on-fourteenth of an ounce (2g). The
biggest bat is the Giant Flying Fox. It has a wingspan of about five feet (152 cm) and it
weighs about two pounds (.9 kg). They both live in Asia.]]
Most bats are insect eaters and have a special way of ""seeing"" in the night called
echolocation. A bat sends out a rapid beeping sound too high-pitched for people to hear.]]
When hunting, the sound waves hit an insect. The waves bounce back to the bat's ears as
echoes. These echoes tell the bat  the size and shape of the insect and where it is located.
In a flash, the bat scoops up the insect. If it weren't for bats, there would be too many
insects.]]
There are fruit and nectar-eating bats, too. These bats help pollinate plants so we can have
food such as avocados, figs and bananas. They also help scatter seeds.]]
A few kinds of bats are meat eaters. They eat fish, frogs, mice and sometimes birds. They
have smooth, sharp, crushing teeth that allow them to eat what they catch - bones and all.]]
Blood is the only food of vampire bats. They are found in Mexico, Central America and 
South America. When the vampire bat finds an animal it makes a tiny cut with its teeth
in the animal's skin. Then the bat laps up the blood with its tongue. The animal hardly
feels the cut.]]
Many scary and untrue stories have been told about vampire bats and people called 
vampires. The famous fictional vampire called Dracula frequently is shown with bats circling
him.]]
Some bats have long, narrow faces. Others have short, round faces. Some bats have leaf-
like shapes on their faces, while others look like dogs.]]
Most bats have very good hearing and can see well. Most bats have a good sense of smell,
too.]]
In the springtime, the female bats gather together in roosts that will become nurseries. There
they will give birth to their babies called pups. Most bats have only one pup at a time.]]
During birth the mother hangs by her thumb claws with her head up. She forms a
basket with her tail membrane. At birth the pup slides from her body into the basket.]]
As soon as the pup is born, its mother hangs head down again. The pup nurses while
being cradled under the mother's wing. The pup clings to its mother's fur, using its own
sharp teeth and claws.]]
The young pup grows quickly. A ten-day-old pup is almost too heavy for its mother to
carry. At three months old, it is flying on nightly hunting trips. When it is about one year
old, it is an adult.]]
Today, in many places bat populations are getting smaller. These bats are endangered.
One reason is that many people still don't like bats and destroy their habitats. Other causes
are pollution and the use of pesticides for killing crop-damaging insects.]]
In many places there aren't enough bats left to keep down the number of insect pests or
to pollinate flowers.]]
People are learning how to help protect bats. Some people provide bat houses where the can
roost. Sometimes people cover bat cave entrances with grill work. Bats are free to come and
go, but people can't enter. Also, there are nature preserves that protect large groups of bats.]]
Bays play an important role in nature. It's fun to learn about them.]]
The Mexican free-tailed bats
that live in Bracken Cave
near San Antonio, Texas eat
about 250 tons (227,000 kg)
of insects a night.
Almost one half of the bat
species living in the United
States are endangered.
Under the Congress Avenue
Bridge in Austin, Texas, one
can see more than a million
Mexican free-tailed bats
roosting. They have become
a tourist attraction.
In China bats are a symbol
of good luck.
Most bats live to be 10 to 14 
years old.
Some bats communicate 
with each other by using
their sense of smell or 
making sounds.
Have you ever heard the 
saying ""As blind as a bat?"" It's 
not true. Bats can see quite
well.
Some people think all bats
carry a disease called rabies.
This is not true. Bats can get
rabies, but no more easily
than any other animal.
Never touch a bat you find
on the ground. It might try to
bite you if it is frightened,
and it could be sick.
There are about 40 species of
bats found in North America.
The most common is the
little brown bat. It can eat
600 insects in an hour!]]

Subjective Criteria

Illustrations: Some support

Vocabulary: Many difficult words

Language: Many descriptive words

Sentences: Multiple phrases

Text structure: Formal

Captions

Prior Knowledge: Familiarity

Features

Topic

Bats

Nature

Endangerment

*Animals

Low Frequency Words

antarctica	characteristics	circling	climates	communicate
congress	crannies	disease	dracula	echoes
echolocation	endangered	fictional	fossil	fourteenth
frequently	habitats	hatched	heartbeats	hibernate
hibernating	kitti's	membrane	mexican	migrate
nature	nectar	nightly	nocturnal	nooks
nosed	nurseries	ounce	pesticides	pollinate
pollution	prehistoric	preserves	rabies	roosting
roosts	separately	shown	springtime	swerve
symbol	tourist	untrue	wingspan