It's also interesting to see Ents as a political force, not just as a force of nature.

The Hobbits sincerely desire a quick intervention. They are quite "human" in this aspect: "Let's go, already! What's with all the discussion? Can't you see what's going on?!"

But the Ents are, if nothing else, thoughtful and deliberate. They have a lengthy memory, and truly weigh all their knowledge, both as a group and individuals. They do not want to move until everyone is in agreement, and truly mull over things. They will not be hasty.

This is somewhat humorous, as it's made clear they can't even say "hello" to each other without it taking hours, never mind getting to an agreement that the Hobbits, are in fact, Hobbits takes the better part of a night.

The Ents only really act when it's made clear there's an imminent danger literally on their border. Then, probrably for the first time ever, they do act quickly and decisively with overwhelming power.