Grady,

>Bats take off at sunset and thus, to some degree, counteract the effect of the birds. The fluctuating bat population is what causes the different amounts of sunshine during the year.

Good grief! You reminded me of one of my favorite songs from "You're a Good Man, Charlie Brown":

12. LITTLE KNOWN FACTS

LUCY
Do you see that tree?
it is a Fir tree.
It's called a Fir tree because it gives us fur,
For coats,
It also gives us wool in the wintertime.

LINUS
I never knew that before, Lucy. That's very interesting.

LUCY
This is an elm tree.
It's very little.
But it will grow up into a giant tree,
An oak.
You can tell how old it is by counting it's leaves.

LINUS
Gosh, Lucy, that's fascinating.

CHARLIE BROWN
Now wait a minute, Lucy. I don't mean to interfere, but-

LUCY
And way up there,
Those fluffy little white things,
Those are clouds,
They make the wind blow.
And way down there,
Those tiny little black things,
Those are bugs,
They make the grass grow.

LINUS
Is that so?

LUCY
That's right. They run around all day long, tugging and
tugging at each tiny seedling until it grows into a great
tall blade of grass.

LINUS
Boy, that's interesting.

CHARLIE BROWN
Oh, good grief.

LUCY
And this thing here.
It's called a hydrant.
They grow all over,
And no one seems to know
Just how
A little thing like that
Gives so much water.

D'you see that bird?
It's called an Eagle,
But since it's little it has another name,
A Sparrow,
And on Christmas and Thanksgiving
We eat them.

CHARLIE BROWN
Lucy, how can you say that?! I'm sorry, but I can't stand
idly by and listen to-

LUCY
And way up there,
The little stars and planets,
Make the rain,
That falls in showers.
And when it's cold and winter is upon us,
The snow comes up,
Just like the flowers.

CHARLIE BROWN
Now, Lucy, I know that's wrong. Snow doesn't come up,
it comes down.

LUCY
After it comes up, the wind blows it around so it
looks like it's coming down but actually it comes up
out of the ground- like grass. It comes up, Charlie Brown,
snow comes up!

CHARLIE BROWN
Oh, good grief!

LINUS
Lucy, why is Charlie Brown banging his head against
that tree?

LUCY
To loosen the bark to make the tree grow faster.
Clouds can make the wind blow
Bugs can make the grass grow
So, there you go
These are little known facts
That now
You know!