Mysterious Tadpoles (story with photos)

In the process of finding places for future fishing, my brother and I drove around the area of the Pakhra and Sword rivers. They acted on such a scheme: In the evening opened in the computer Google-maps, found the right river (tried to search within a radius of no more than 30 kilometers) and moving on the map along it, noted all the sharp turns and spills. Special attention was paid to those areas, which do not have a good entrance to the car, and from the potential parking to the intended place of fishing was required to walk 500 +-meters. In the process of viewing Google Maps, we noticed that near one of the villages there is a cascade of three ponds, connected by a stream. As near, on distance about a kilometer, there was an interesting section of the river Pahry which we have put in a plan of fishing, have decided to see, what it for reservoirs.
The car had to leave on the edge of the forest, and further to the ponds was a forest hardly noticeable path. To the right and to the left of it above human growth stood, as in the prehistoric forest, dry stalks of last year's hogweed.

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A fence and some buildings appeared in front. Along the fence, on a narrow path we finally snuck into the pond. This pond was very picturesque. His upper part went to the forest. And from this part of a pond flowed a stream in the next reservoir of a cascade...

In the pond, in places stuck huge snags, and the coast somewhere littered with fallen trees. All this created a feeling of wild and little visited pond.

But the biggest impression on us was made by tadpoles! To say that there were many-nothing to say)). The entire open sun part of the pond is literally infested these future frogs. They are crowds of warming on a shallow concrete dam...

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... Moved along the shore from one section of the dam to another....

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... and meters in 20-30 from the coastline, on open water, formed gigantic clusters with some bizarre, chaotic-incomprehensible pattern of movement...

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And the tadpoles itself was clearly clear what they were doing and why. All the movements and constructions of these huge flockss seemed to be painfully coordinated and somehow meaningful.
At first I decided that tadpoles all this-a common strategy of protection against predators, as in many small animals, birds and fish. Maybe that's the way it is. But in the 20 minutes that we spent on this pond, no flock of tadpoles (and there were more than 10 on the surface of the pond) was not carried out any attack in the water, or from the air......

Tried to search the internet for an explanation of such behavior tadpoles. But nothing like the truth found... Only in one note (most likely fake) it was said that tadpoles in this way try to make contact with the person and something to tell him)))).
If any of you, friends, knows the answer to the question of mysterious tadpoles, please subscribe in the comments!

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