Elephant bulls grow significantly larger than elephant cows. At almost four meters tall, they are the second largest land animals after giraffes. They also weigh five to six tons, making them the heaviest of all land animals. African elephant bulls usually separate from their herd when they are around twelve years old. They are then mature enough to find their own food and defend themselves, and roam the country with other bulls or as loners in search of another herd. An elephant's memory is proverbial: even after many years, it can remember where waterholes are located or recognize elephants from which it has been separated. Elephants recognize their own reflection. Very few animals apart from elephants can do this.