they crawl on leaves
they fly through the air
they even dig in the ground
insects are practically everywhere
they live on every continent including
antarctica
although they prefer to live in warm
areas
you are probably familiar with some
common insects like bees
ants and butterflies
but insects are the largest group of
animals on earth
nearly a million species have been
identified so far
and scientists estimate that there could
be millions more just waiting to be
discovered
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insects are invertebrates or animals
that do not have backbones
in fact insects do not have any bones at
all
instead they have a hard outer shell
called an exoskeleton
that gives them their structure
insects have three main sections of
their bodies
the head
the thorax
and the abdomen
they have six legs that are connected to
the thorax
most insects also have wings and
antennae
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although insects breathe air they do not
have lungs
instead they have a system of tubes and
sacs through which air may pass or be
pumped
this system can only carry air so far
into the insects body
and it is this that limits how large
insects can grow
although there are some very large
insects on our planet they cannot grow
as large as other types of animals
because after a certain size they could
not get enough air into their bodies to
support themselves
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another interesting insect
characteristic is their eyes
insects have a special kind of eyes
called compound eyes
compound eyes are made up of hundreds or
even thousands of tiny light-sensitive
units
each unit sees only a small part of the
insect's surroundings
but all of them together create a mosaic
image
a pattern of light and dark dots
overall insects do not see as well as
humans do and only some can see colors
but their eyes are excellent at
detecting motion
insects are cold-blooded which means
that they cannot control their body
temperature
that is why insects usually live in warm
places
and why you do not see as many insects
during the winter as you do during the
summer
to survive the cold some insects enter a
state called diapause which is their
version of hibernation
and will not become active again until
warm weather returns
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insects hatch from eggs
and although some insects hatch as
basically small versions of the adults
of their species
others go through an incredible change
before adulthood
it is called metamorphosis
from a word meaning to transform
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the most famous example of metamorphosis
in insects is the
butterfly
butterflies begin their lives as
caterpillars
and spend a few weeks eating and
increasing in size
once they are fully grown the
caterpillars will attach themselves to
the underside of a leaf or branch and
form a pupa or chrysalis
the chrysalis hardens into a protective
case
and over the next few weeks the
caterpillar inside transforms into a
butterfly
when the butterfly is ready to emerge
the chrysalis splits open
but the butterfly cannot fly yet
it hangs upside down
pumping fluid into its wings to make
them expand and slowly opens and closes
them to help them dry
once its wings are ready the butterfly
takes off to find flowers to drink from
eventually it will lay eggs of its own
and the cycle starts all over again
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crawling or flying
alone
or with thousands of friends
insects by the millions
are incredibly important to life on
earth
some insects are beneficial to humans
while others are pests
but no matter their shape
size
or color
insects make a big difference for such
small creatures
i hope this helped you learn more about
insects today
goodbye till next time
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you