The little roofed sheds, seen throughout the Balinese rice fields, are used mainly to house a cow, but some of them are used as shelter for the flag waver.  As the rice ripens huge flocks of sparrow like birds descend on the fields to eat the rice.  In order to prevent this the Balinese setup long strings, held up with bamboo poles, with scrap plastic bags attached.  The strings all emanate from the little shed where the flag waver sits ready to shake the strings and scare off the birds when they arrive.