Herons generally live near the water bodies and in the meadows where cattle come for grazing. There is vacant piece of land in our home which is used by cattle mostly buffaloes for grazing. There are small pools of stagnant water in it. In the neighbourhood are fields which are cultivated round the year.
Here you can spot plenty of white herons. They seem to be meditating standing on one leg. At times they are completely inactive. But as soon as the cattle come for grazing, they become active. They fly from their posts and land near the cattle. You can see them following the grazing animals. The reason for this is that as the animals pull the tufts of grass from the ground, the insects present there start flying and become the food for these birds.
Sometimes, one of them sits on the back of the cattle and enjoys the ride while surveying the surroundings for flying insects. At times, they fly together in graceful formations and again land nearby the animals.
When the fields are ploughed, you will find them moving behind the tractor or the bullocks. The reason is again the same- the insects. I took some pictures.