Banded mongoose (Mungos mungo) have been observed to show certain social traditions. Each pup pairs up with an older (escort) mongoose and learn how to imitate them. Two scientists placed an artificial food item (rice and fish contained in a plastic egg) and watched what the escorts did to open the eggs: they held them with their paws and bit into them. Pups observed their escorts and, months later, had learned the technique and could imitate it. Some other escorts did something completely different: they threw the eggs on a hard surface. Well, their pups also learned this technique from their escorts.
-- Nature 465, 668 (10 June 2010)