Answer:
Lambs are mostly curious. Their personalities are quite dull until they are about a week old, then they find their niche with the other lambs and start goofing around and play king of the hill (they find a mound of dirt or a hay bale, jump on it, and try to knock each other off). They start to lose their personalities at around a year or so, however, the bold and confident sheep tend to retain their personalities well into adulthood.