……

"Boom la la ......"

It seems that the sound of wings agitating is coming from the downstream direction, and judging by the density of the sound, it should be a large number of small flying creatures.

Yang Lingtian listened attentively and calculated in his heart, and his mind turned to see what was coming.

"Hula ......"

Standing on the cliff with his hands in his hands, he waited quietly, but what appeared surprised him.

What caught my eye was countless red points of light, densely packed with countless red points of light floating in the air, coming towards this side.

"Holy, "ghost fire"? ”

Yang Lingtian's heart tightened, and the things that came from afar seemed to be a little unexpected, which made him worry.

His feet swayed slightly, his body moved slightly, and he tucked himself into the recess of the stone wall next to him, hiding his body as much as possible.

"Hula ......"

The sound of wings agitation was getting closer and closer, and Yang Lingtian's eyes flashed with a new idea.

Judging from the whistling sound, there was no doubt that it was a small flying creature, and he already had some guesses in his heart.

As the distance of the "ghost fire" in the sky was pulled, the whole picture of the things in front of him gradually entered his sight, which made him greatly relieved.

"I thought it was some strange thing, but I didn't want it to be this, I scared the king to death!"

Yang Lingtian slandered in his heart, looking at the "ghost fire" flying through the sky.

It is the size of a mountain mouse, with a short neck, broad chest and shoulders, well-developed breast, and slender hips and legs.

It bears thin wings on its back, and its body is covered with hair, and the back is gray, brownish-yellow, brown, or black in different shades, while the ventral side is lighter in color.

This is exactly a bat, and if there is anything strange about the bats in this underground world, it is that their size is much larger than that of ordinary ground, and then there are these big red eyes that don't know what the principle is.

"It's a bit of a doorway for the big red eyes that don't seem to know what the mystery is."

Yang Lingtian sighed, you must know that these "red eyes" can be seen from a distance of dozens of meters, that is to say, these are their own light, and as far as he knows, only cats, jackals and other nocturnal animals have characteristics.

This is very interesting, bats rely on sound waves to locate objects for the purpose of seeing, while the "red-eyed bat" in front of them may see with their eyes, and may also have night vision.

"Hula ......"

The whistling sound passed in front of him, and Yang Lingtian remained motionless and hid his body in the crack of the stone, naturally not being discovered.

In line with caution, and not knowing whether the "red-eyed bat" was interested in him or not, he didn't provoke these little things that didn't look easy to mess with.

In a few moments, thousands of "red-eyed bats" finally roared past, and the scene covering the sky and the sun was still very shocking.

"Da ......"

Yang Lingtian lifted his steps, stepped out, and continued to walk downstream.

Suddenly, the second claw he raised lightly smacked in the air, and the second step did not fall for a long time.

The large pliers on the right side were raised, rubbing their chin constantly, with a pensive look.

"What are these "red-eyed bats" doing? ”

This doubt has been around my heart for a long time and refuses to dissipate, what is upstream?

Nothing, clear water, moss-covered stone walls, nothing else, two slightly larger stone crevices.

"Take a walk after dinner?"

Yang Lingtian's thoughts flowed, and suddenly, a bright light crossed his heart.

"Shamrock!"

The small figure of the "clover" comes to mind, and it is okay to say that the distance upstream is really barren, there is nothing, and the only thing that is special is the "clover".

Holding the idea of "looking at a lot of pieces of meat", Yang Lingtian looked at it and decided to go back and have a look.

"Da ......"

The second step fell gently, but the direction of travel was already far from the same, and he turned back.

"Da ......"

The faint sound of footsteps was soft, and Yang Lingtian's limbs and claws were lightly raised, and he walked very lightly, for fear of startling the snake.

You must know that bats are masters of playing with sound waves, and coupled with their possible ability to see, he can't afford to be careless.

He doesn't care about the combat effectiveness of the "Red-Eyed Bat", but who knows if it will have any tricks, and besides, the senseless fight is really unnecessary.

The faint "ghost fire" was floating all over the sky, and the speed of the "red-eyed bat" was not slow, and it didn't take long to reach the end of the upstream.

"...... Uproar"

A uniform voice came out, and in Yang Lingtian's surprised eyes, thousands of "red-eyed bats" were like an army, "orders and prohibitions", and the movements seemed to have been rehearsed thousands of times.

The huge swarm of "red-eyed bats" flowed like water, and they all stopped in front of the "clover".

"Sure enough!"

Yang Lingtian looked at it and secretly said that he was extraordinarily smart, which he had guessed, and he really deserved the name of a former genius.

"Hoo ......"

"Hoo ......"

A few whistling sounds came out, and I saw three "red-eyed bats" flying out of the bat swarm first, which were three beings that were obviously one size larger than the others of the same kind.

The three "big red-eyed bats" are divided into one large and two small, the larger one is almost three times the size of the ordinary similar size, and the two small ones are about twice the size of the ordinary similar body.

"...... Uproar"

Thousands of "red-eyed bats" were in a commotion, and their wings were stirring one after another, as if they were excited, and their mouths were raised as if they were shouting.

"Huh?"

Yang Lingtian's heart froze, and a bad feeling appeared inexplicably, and he didn't have time to move, and he couldn't even make effective movements, and the change suddenly occurred.

"Squeak......

The high-pitched, silent howls roared in all directions, endlessly, wave after wave, wave after wave, higher than wave after wave, drilled into the ears.

Deafening, shocking, shrill sound waves reverberated in my head, like someone scratching glass in their ears.

Almost instantly, my brain went blank, and I felt dizzy.

"Ultrasound!"

The word "ultrasound" came to Yang Lingtian's mind, and the ultrasonic wave evolved by the "red-eyed bat" actually entered the category of "weapon", how shocking it was.

Sound waves exist at frequencies, and the frequencies of sound waves that can be heard by the human ear are generally between 20 and 20,000 hertz.

Less than 20 hertz is called infrasound, higher than 20,000 hertz is called ultrasound, regardless of infrasound, ultrasonic can not be caught by the human ear, but it is real, can act on the human body and produce corresponding consequences.

That is to say, there are countless sound waves of all kinds in nature, and the world is extremely noisy, never quiet, but humans can't hear it.

Yang Lingtian didn't have an instrument, so he didn't know what the upper limit of the sound wave frequency that his "crayfish" could catch, but this kind of fluctuation that didn't hear the sound but really acted on his body was ultrasound.

You must know that he has undergone two evolutions, and his body size of fifty or sixty centimeters has a huge strength, but you can think of the strength and density of his muscles, bones, etc., so that there is such a big reaction under the ultrasound of the "red-eyed bat", if it is replaced by an ordinary human being, he will have to peel off his skin if he is afraid of not dying.

……

Thank you for the recommendation votes of "Walking on the Road...... and "Ming"!

(End of chapter)