During the winter months, ants go into a hibernation-like state and do not emerge outside until the spring. They stay underground throughout the winter where it is warmer and they do not have to try to survive in the outside temperatures.
Many people consider hibernation to be a state of deep sleep during the winter, but hibernation simply refers to a slowed down body state. Any animal can go into a hibernation status by slowing their body down in the winter and staying inside, whether it be underground or in a home. Ants will conserve food during the late part of fall and will keep the food available in their underground tunnels throughout the winter. They will slow their body down in the winter so that they do not need as much energy and can conserve the food that they have saved.
During the winter, ants will go into their underground tunnels and will block off the entrances and exits. Doing this prevents the cold air from entering their tunnels and will help to keep them warm. They will often huddle together to help stay even warmer, but do not have to do this in some areas where the ground stays warm throughout the winter. Ants that live in Canada and in the cold New England areas are equipped with a special substance in their body. The substance can be secreted throughout their body and will help prevent them from freezing.