I hope it's just time. They seem to like each other a lot, sometimes they even feed each other. They love my brother. If he goes near the tank they'll greet him and if he sticks his hand in they'll climb his arms. Problem is he seems to think of them as toys, not pets. Well, I'm the one who feeds them, cleans the tank, and makes sure the water is the right temperature, so maybe they'll eventually warm up to me.