Definition: Given a paragraph about movies and a set of conversational questions and answers about the paragraph, say whether the passage contains sufficient information to answer the follow-up question. Say Yes if it is answerable; otherwise, say No. The paragraph has the prefix 'CONTEXT:'. Each conversation question has a prefix `Q:` followed by the answer prefix `A:`, and the follow-up question has a prefix `FOLLOWUP_Q:`.
Input: CONTEXT: I don't have official source or script to draw from. However, my read on that scene is that they were waiting for the humans. The whole nest seems to be in a sort of button-up-and-fortify mode. The most the Vikings sniff of a dragon is the tail that gets whisked out of sight. This is more than likely intentional - note that the eerie sound that continues while the Vikings land and fortify continues right up until they punch the hole. It's a very similar sound to the sound the other Alpha dragons make in the second movie, while exerting dominance or control. The Alpha is holding it's nest on tight guard, possibly to pounce once it feels right. That all seems to go out the window when Stoick signals a fireball launched in. Whether that was just an agressive surprise, or read as some kind of direct challenge, I couldn't say for sure. The dragons in the tunnel though, didn't move until that moment, and it mostly seems to be an action of I'm-getting-the-heck-out-of-the-way as that Alpha decides to muscle out and deal with this personally.  <sep>  Q: Why didn't the dragons leave their lair earlier?

Yes