Usual easy mark

From last autumn through this winter, I see what the group which I do not arouse in the pond nearby does. Only four of them or five of them swim together even if I say a group. It is the group of what kind of relations or does not know it, but swims in the members who, anyway, were fixed whether it is a friend as it is a family. As I left for the north country when it was full-scale spring and could not see the figure, I put it on a video first.