Thai Waltzing Water Boatmen.

At the first glance – just insects in the slack water… but how interesting they are!
Thank you for letting me know more about them: water measurers (Hydrometra dimock,), water skaters (Gerridae dimock), water striders, pond skaters and so on… the name I like most: “Gerris lacustris” –sounds poetically, but for the fact they are skilled raptors and the professional pirates of the insects world. They feed by insects fallen on the surface of the water. As a spider knows that an insect is captured in his net so the water measurer knows that an insect is fallen by the pattern of the waves.
Striking the surface membrane and making waves males are looking for female during definite period. Males defend territories by swimming leaves so when the rival comes closer the “resident” emits frightening waves “skips pebbles on the water” saying “this is my house”. Females don’t have their territory and don’t frighten anybody. Males never fall on the female and distinguish her slide from the match’s.