Think about all the animals you see where you live.  Maybe you have seen dogs, cats, birds, and a rat!  Would you see the same animals in other cities?  What about different countries?   Now think about all the plants you see where you live.  You see trees, bushes and even weeds that grow in the sidewalk.  Think about the last time you walked by someone who smelled bad.  One of the reasons they smelled so bad was because of very, very, very small bacteria!  Bacteria are only one cell, and are the simplest organisms on earth.  Everything that is alive is called an organism.  Organisms can be tiny cells, plants, or huge animals.  Some live in the ocean, some in deserts, and some in the city.

A Maltese might be cute, but would not live for very long in the desert.


Being alive is not easy.  A cat may be able to live in your neighborhood.  There's a place for it to sleep, someone might feed it, or it can find mice or trash to eat if it gets really hungry.  In a city, there probably are not many other animals that can eat cats.  The most dangerous thing for a cat might be a car driving down the street!  However, what if you put that cat in a forest?  There aren't a lot of safe places where a cat could sleep.  Even if it finds a place to sleep, there are animals in the forest that can eat the cat.  Owls can grow big enough to pick up a small cat.  Coyotes could easily eat the cat!

Coyotes. Not a cat's best friend.


Plants also cannot live anywhere they want.  There are some plants that need to be watered every single day.  If that plant is put in a place where it only rains a little bit, it could not stay alive.  On the other hand, some plants can only live in places where it only rains a couple times a year.  How often does it rain where you live?  Which of these plants could grow in your area?  Most organisms can only live in some environments.

A Eucalyptus tree. Please do not climb to the top. Please.


Your environment is everything around you.  Your classroom environment might have a window, chairs, other kids, a teacher, lights, walls, and paper. The environment of an apartment or house might include a couch, a table, a refrigerator, shelves, books, food, and a sink. An environment can be bigger than a room.  A beach environment would have sand, water, waves, the sun, fish and seagulls. You can say the environment of your street might have other houses, other buildings, cars, the sun, wind, and air for living things to breathe.  Anything that is living or not living can be called a part of the environment.

An alley cat, not a forest cat.


A beach environment is made of many things.  Living things like the birds and fish are one part.  Non-living things, like the sand, the sun, the water, and waves, are very important too.  These different parts of an environment are called environmental factors.  Environmental factors are any part of the environment and can be living or non-living.  In the ocean, environmental factors might be how hot the water is, how strong the waves are, or how many birds are on the beach.

The Grand Prismatic Spring in Yellowstone National Park is too hot for people to swim in, but is a home for millions of bacteria!


Scientists use different words to describe the environment.  A characteristic is a part of something.  The street has many characteristics.  It is black, has white or yellow lines, is made of many small rocks that are glued together, and cars drive on it. Characteristics of a pencil might be that it is yellow, made of wood, has lead in its middle, has an eraser, and is used for writing.  Organisms have characteristics that help them live with the environmental factors where they are.  Fish have fins to swim in water, and roses have thorns so animals don't eat them.  Mice are small so they can crawl in and out of places to find food.  Organisms fit into their environments like a key fits into a lock.