In many parts of the United States, temperatures are falling. This change of season, from summer to autumn, gives Americans many things to watch. Many people travel to areas of the U.S. that are famous for autumn leaves that change into brilliant shades of red, gold and orange.

Something else to watch is the antics of squirrels! Squirrels provide some of the most interesting and entertaining behavior in the natural world.

Now, I use the word "antics," meaning silly or funny games, because that’s what it looks like.

But I am not being fair to squirrels. They are actually doing something most important -- gathering and storing food for the winter months.

The fact that squirrels are doing an important activity, however, makes them no less entertaining to watch. The animals hurry across the ground, digging holes to find food or to find where they buried food.

They chase each other around trees. They jump from one tree limb to another, higher and higher up in the tree, looking for nuts and seeds. Sometimes, squirrels drop this food to the ground below, and sometimes they hit people passing by.

As I said earlier, this behavior is very entertaining to watch!

These woodland creatures do not stay still for very long. And they are good at collecting things. So, it is not surprising that American English has a couple of expressions with the word “squirrel.”

First, there is the adjective squirrelly. Now, "squirrelly" has several definitions. The most common one describes someone who is unusually active and unable to sit still -- much like a squirrel.

Another word with the same meaning is restless. When talking about word choice, "restless" may be more common in everyday speech, but "squirrelly" is much more fun!

Let's hear it used in an example. "At that end of a school year, students may get a little squirrelly (restless) sitting in a classroom. It's best to let them run around outside during the day."

In this example, you can almost imagine a classroom of children suddenly turning into a group of squirrels running around and unable to sit in their seats! So, the word you use depends on the feeling you want to create in your sentence.

"Squirrelly" can also describe someone who is acting very strange or crazy -- again, like a squirrel. A word that means close to that is eccentric.

This meaning of squirrelly may come from the fact that the main food in a squirrel’s diet is nuts. In American English, "nuts" is a slang expression for crazy.

"At the party, she behaved squirrelly (eccentric) the whole night -- walking quickly between rooms, hiding in corners and interrupting conversations with high-pitched laughter. She gave everyone a very odd impression."

Finally, the adjective "squirrelly" can describe someone or something that seems to be dishonest. A more commonly used word that means the same thing is shady.

Let's hear an example. "That business deal sounds squirrelly (shady) to me. If something sounds too good to be true -- it probably is."

So, that is the adjective. We also have a very useful expression from the world of squirrels -- to squirrel something away.

Okay, so we know that squirrels collect nuts, seeds and other things to eat. Then they hide them away to survive winter weather, when food is hard to find.

People can do the same thing. When we squirrel something away, we put something in a safe or secret place so that we can use it in the future. When we collect or save things in an unusual, or even unhealthy way, you could use the word hoard.

Here's another example. "She has squirreled away (hoarded) magazines for years. There are stacks and stacks in her attic. I'm not sure what she is saving them for but she won't get rid of them!"

The things people squirrel away usually aren't nuts and seeds. We most often squirrel away money for the future.

"When he retired he was able to live quite comfortably. He squirreled away over $400,000 in the bank!"

But we can squirrel away anything that is important to us and that we want to use later.

"She squirreled away her favorite color of wool yarn as if they weren't going to make it any more. She has more than 30 rolls of it in her closet!"