Snakes do not migrate or really change their habitat in the winter, but snakes in colder climates do move underground or into protected crevices. In climates that do not see colder temperatures, snakes may stay above ground and be seen as normal throughout the year.
When the temperature drops, snakes congregate together in the designated hiding place so that they can keep warm by sharing body heat. The snakes will stay knotted up together until the temperatures rise again. Once spring comes, the snakes disperse out of the hiding spot to sun themselves on rocks before resuming their normal eating and activity habits.