Story: Jenny and Carlos Get Out of the Rain
Chapter Two: Bat Shows Off the Cave
Jenny switched on the flashlight the bat had discovered. Now they could see in the
dark. She and Carlos stared at the underground world in amazement. Strange rocks
decorated the cave. Some hung from the ceiling, like icicles. Others, like pointy tree
stumps, grew from the floor. Flowery crystals grew from the wall where Carlos stood.
Jenny stared at curtains of pinkish stone draped down the walls across from where she
stood. Both children were struck speechless in this dark and lovely place.
For the first time, they could see their cave guide. The bat hung upside down by the
little claws of his hind feet. He dangled from a ledge on the cave wall. They could see
his brown snout and big ears. Dark, glittering eyes stared out from a black mask. A
coat of chestnut brown fur made him look warm and cozy in the dark cave. Strangest of
all were his paper-thin black-brown wingsfolded up close to his body like brown
paper napkins.
The children had never imagined anything like this cave. As their eyes got used to
the faint light of the flashlight, more and more curious structures appeared. They didn't
know where to begin looking.
The cavers I met made maps of the cave. Too bad you two don't have a map,
teased Bat.
The children did not think it was a funny joke. But they wondered.
"What's a caver?" they asked.
Oh, they are people who like to explore caves, Bat explained.
They wear special clothes and boots. On their heads, they wear helmets with
lights. They also carry flashlights. They climb up and down the cave walls with ropes.
They act pretty goofy sometimes and laugh a lot. They draw little maps in
notebooks.
"I wish we had some caver equipment like that," Carlos said. Many questions were
going through the children's minds.
How did this cave get here?
Why didn't anybody at science camp know about this cave?
Was it safe to be here? Would rocks fall on their heads?
Where were the water sounds coming from?
How would they get out of here?
Bat's squeaky voice broke into their thoughts. You see why I wanted to find
you the flashlight, he commented. Let me show you around
now.
Bat spread his little brown wings. He launched himself from the cave wall and
flapped around in circles over the children's heads.
"Hey Bat," Carlos asked, "how do you see in the dark with this sonar you told us
about?"
Well, remember the echoes you heard? It's kind of like that. The squeaks you
hearI use those for talking to other bats mostly. I can tell how close something
is by making a signal that you humans can't hearonly I can hear it. The signal
goes out and hits thingslike the wall. Then, an echo bounces back and hits my
big ears. If it comes back fast, I know I'm going to hit the wall or something pretty
soonlike you and Jenny did back there. So I make a turn. If the echo takes a
longer time to come back, I can keep going for a while without hitting
something.
"Do you always use sonar?" Jenny asked.
No. I use my eyes when we fly out of the cave in the evening, before it gets
really dark. And in the cave, sometimes I forget to use my sonar and I bump into things
just like a human. It's embarrassing.
Jenny giggled. "It's like you have two pairs of eyes," she said. Carlos took the
flashlight and looked around at the strange rock shapes. He asked Bat how they got
there.
Bat flew to a nearby rock hanging from the ceiling. He hung from the ceiling and
started to answer. Well . . .
"And why is everything wet?" Carlos interrupted, "I've heard water dripping from
somewhere ever since we got in the cave. And somewhere I can hear a stream
too."
. . . it took water and stone to make this cave. See the rock all around us? It's
called limestone. The cave used to be solid rock. It used to have cracks in
it, but the cracks got wider and wider until they turned into caves and
tunnels.
"How do the cracks get so big?" asked Jenny.
Water trickles down through the earth above us. Especially when it rains like
today. And it rushes through the limestone in underground streams. When the water
goes through cracks in the limestone, the limestone dissolves away slowly, because
the water has a little bit of acid in it. It's a little sour.
As the limestone cracks get wider, more and more water can flow through the
cracks. After a while, the water can become an underground stream.
"You mean water can make rock go away? Like water makes soap go away in the
bathtub?" Carlos asked.
Well, I don't know what soap is.
Bat thought for a minute.
I've watched the cave explorers make tea. Sometimes they put sugar in the
tea and the sugar goes away. It dissolves. The rocks are like the sugar.
Even hard rocks like limestone dissolve. But in a cave it happens slowly.
Over a long timeoh, like twenty-five thousand yearsthe cracks get bigger
and bigger. Some of the cracks turn into tunnels, like the one you just crawled through.
After awhile the tunnels get bigger and bigger. Some of them join with other tunnels
and we get big cave rooms.
"Did the tunnels dissolve into big rooms like this?" Jenny asked. "Is the rock in this
cave still dissolving?"
Oh yes. The rock in this cave is dissolving all over the place. Listen to all that
water dripping! The tunnels grow into big rooms. Cave explorers call big cave rooms
'caverns.' Later on, I'll show you a place where the whole ceiling is dissolving away.
Eventually, it could become so thin it will collapse. Then it's called a sink
hole.
The sound of drips went on. The children couldn't tell which drips were drops or
which were the echoes of drops. They wondered how many drops could carve out
such a big thing as a cave. Carlos thought it would be even slower than the growth of
tree rings they had seen at science camp.
"What about these weird shapes?" Jenny asked. "How do they get here? We don't
see these above ground."
The Bat went on. No, you don't, Jenny. It's water again. When water drips
through the limestone, it picks up tiny bits of limestone. You know, dissolved in the
water, just like sugar in tea. So you can't see it. When a drop hits the ground, the water
dries up. The limestone in the water gets left behindor deposited. A coating of
tiny crystals slowly builds up.
Bat looked at the icicle shapes hanging from the cave ceiling. Or
down, he added. That's how these strange stones take shape. And it's
slow again. It takes thousands of years to make some of these rock
shapes.
It's funny, laughed the bat. In one part of the cave, water
deposits the crystals. In another place, water dissolves crystals away.
"I don't believe this. Water can't do all this," said Jenny doubtfully. She stepped
back to look at the rocks hanging from the ceiling.
"Carlos!" she whispered. "Look there! Shine the light in the water. Something's
over there. Look! There's . . . oh, I don't believe it!"
Carlos and Bat moved closer to see what she was talking about.
"Watch out Jenny!" Carlos shouted.
Just in time, Jenny glanced behind her. A small stream was flowing through the
cave behind her. It was a fast-running stream, but she had not heard it. Her foot dipped
into the stream. Splash!
Jenny yanked her dripping foot out of the water as if she had stepped into a hot
campfire.
"Oh no! My foot's all wet," she complained. Carlos shone the flashlight on her as
she shook off the wet foot. The worried Bat flapped around in circles.
Suddenly Jenny put her foot down. She stared into the stream.
A silvery white creature glided through the water. Then it darted off like a flash of
light, a watery ghost. It disappeared behind a rock.
Oh, hi fish. Bat squeaked. This is Jenny. Sorry she fell in your
stream. She won't hurt you.
Bubbles streamed up from the fish, still hiding behind a piece of limestone. "He
nudged my foot," Jenny said. "I think he was trying to say hello." The children listened
as the bat squeaked excitedly.
I'm glad the fish is back, said Bat. Last year, limestone caved in
under a garbage dump on the surface. It caused a sink hole. The garbage and
pollution in the sink hole fell into this underground stream. Most of the cave fish got very
sick from the poisons in the garbage. This fish was OK because she was laying eggs in
a place that didn't get the poison. You can see why troglobites don't like people very
much.
"Troglo-whats?" Jenny and Carlos asked at once.
Troglobites, cave dwellers, the bat explained patiently. Don't you
humans know anything? The cavers knew the word. They say that troglobites are
animals that can't ever leave the cave or live anywhere else. Here we have white
troglobite daddy longlegs and salamanders and centipedes. They look different from
their surface cousins, but they are close relatives.
Now, many have no eyes, and are pale or white, like Ms. Fish. In the stream
we also have some pale white shrimpy creatures and crayfish.
"So why are troglobite fishes white?" asked Carlos.
Carlos, laughed the bat, turn off your flashlight. Can you see any
colors?
The cave went dark. "No, of course not," Carlos responded.
Right. Troglobites don't need colors in a cave. So their bodies don't waste
energy making colorful skin or scales. Just like they don't need eyes either.
"I liked Ms. Fish," thought Jenny out loud. "All silvery in the stream. She looked like
a ghost. I can't remember seeing her eyes."
"Are you a troglobite, Bat?" she asked.
No, I'm a trogloxenea cave visitor. I spend a lot of my time in the
cave I like it here. But I leave the cave when I want to, especially at night.
Troglobites have to stay here. They've changed so much that they can't live up there
anymore.
Used to be there were really big trogloxenes, like cave bears. Cave
earthworms are cave visitors too. If they wanted to, they could live in your
lawn.
"Bat, we must be cave visitors, just like you,"Jenny said.
Carlos laughed. "Yeah. We're trogloxenes, right?"
Now you two are getting silly, the bat said. But you're right, I
think.
"Do troglobites find their way around with sonar like you?" Carlos asked.
Oh no. Ms. Fish can't see but she can feel things really well with her skin and
smell things in the water. In fact, I bet she can feel the water shake when you talk. And
crickets have really, really long feelers, he said. They can feel and smell you coming
long before you can spot them.
Are there any other kinds of animals in the cave? asked Carlos.
Why yesthe troglophiles, the cave lovers. These animals, like some
kinds of cave spiders, could live above, but they spend their whole lives in a cave
instead. They like cave life.
By this time they were walking through the tunnel. Carlos was thinking about cave
animals, not paying much attention. He certainly wasn't paying attention to everything
being so slipperythe moldy rocks on the cavern floor, the slimy cave walls, and
oozing mud in the tunnel.
Carlos suddenly slipped and fell back. The flashlight banged on the wall and
clattered down on the rocks below. Light flickered for only a moment on the cave
wall.
"Oh no!" cried Carlos, feeling around in the dark. The light died. The cave was lost
again in thick darkness. Even the bat flapped in surprise.
For a moment, Jenny imagined that she had become a troglobite. Had she turned
white? Were long feelers growing out of her head? Just to make sure that she was still
a normal human, she reached up to her face. Yes, she still had eyes, but they were
eyes that could not see. She had no feelers to guide her through the tunnel.
My ears! Jenny thought. Without my ears and my hearing, I
could be lost forever in this cave!
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