[While he spends most of the days hanging out with the many different dragons and getting to know as many of them as he can, by the time the sun sets Merlin's been going down to the center of that ice structure, deep where the Alpha rests.
Perhaps you've noticed he seems to disappear after being very noticeably all over the place the rest of the time, or maybe you're visiting the old dragon with him, or maybe you're simply following the deep rumbling noises that occasionally come from it... Either way, you'll find Merlin hanging out in front of the giant creature, watching and helping out as the other dragons bring food to him in batches.]