Hibernate is a state of inactivity that some animals enter during cold months to conserve energy. During this time, their body temperature drops, and their metabolism slows down significantly. This allows them to survive on stored body fat when food is scarce. Common animals that hibernate include bears, ground squirrels, and hedgehogs. They typically find a safe, sheltered place to rest, such as a den or burrow. Hibernation can last for weeks or months, depending on the species and environmental conditions, and helps them endure harsh winters until food becomes available again.