http://www.imdb.com/title/tt1080016/

After the events of "Ice Age: The Meltdown", life begins to change for Manny and his friends: Scrat is still on the hunt to hold onto his beloved acorn, while finding a possible romance in a female sabre-toothed squirrel named Scratte. Manny and Ellie, having since become an item, are expecting a baby, which leaves Manny anxious to ensure that everything is perfect for when his baby arrives. Diego is fed up with being treated like a house-cat and ponders the notion that he is becoming too laid-back.