No, the ants should remain within Ant Mountain for the entirety of their life cycle. Without a queen, they will not survive outside to form their own colony. Their life cycle within Ant Mountain should last 2-4 weeks.
Yes, the ants depend on you for their food. Place a tiny piece of carrot or apple in Ant Mountain. It should be about the size of a popcorn kernel. Once the food has disappeared, replace it with a fresh piece. Do not overfeed.