In the 1930s we lived in a swamp in Central Louisiana. Our home was the only house on a dirt road one and one half miles from the main highway which was gravel. Our livestock enjoyed open range, but in winter they usually stayed close by to get supplemental food.
In cold weather hogs in the wild use their front feet to rake leaves and straw to create a bed. Then several get in the bed to sleep. During the night as the temperature drops the ones on the outside of the bed get cold and struggle to get on the inside. This causes unrest among the bedfellows and they voice their annoyance by grunts and squeals. We referred to this as pulling cover.
Our home was built on the pier and beam method so the floor was about 18 inches off the ground. As with most country homes in that day there were cracks between the wide planks in the floor and in some places one could see the ground.
On the coldest winter nights our hogs would make a bed under the house. As the temperature dropped, sure enough, they began to pull cover. Who can sleep with a bunch of hogs grunting and squealing under his bed? There was only one thing to do. Mother would get up, build a fire in the wood stove and heat some water that she would then pour through the cracks in the floor onto the hogs. With a swoosh they would leave for the woods.