‘Are the stories about it true?’ asked Pippin.‘I don’t know what stories you mean,’ Merry answered. ‘If you mean the old bogey-stories Fatty’s nurses used to tell him, about goblins and wolves and things of that sort, I should say no. At any rate I don’t believe them. But the Forest is queer. Everything in it is very much more alive, more aware of what is going on, so to speak, than things are in the Shire. And the trees do not like strangers. They watch you. They are usually content merely to watch you, as long as daylight lasts, and don’t do much. Occasionally the most unfriendly ones may drop a branch, or stick a root out, or grasp at you with a long trailer. But at night things can be most alarming, or so I am told. I have only once or twice been in here after dark, and then only near the hedge. I thought all the trees were whispering to each other, passing news and plots along in an unintelligible language; and the branches swayed and groped without any wind. They do say the trees do actually move, and can surround strangers and hem them in. In fact long ago they attacked the Hedge: they came and planted themselves right by it, and leaned over it. But the hobbits came and cut down hundreds of trees, and made a great bonfire in the Forest, and burned all the ground in a long strip east of the Hedge. After that the trees gave up the attack, but they became very unfriendly. There is still a wide bare space not far inside where the bonfire was made.’...
From later on in our chapter, after meeting Mr. Bombadil:
It became difficult to follow the path, and they were very tired. Their legs seemed leaden. Strange furtive noises ran among the bushes and reeds on either side of them; and if they looked up to the pale sky, they caught sight of queer gnarled and knobbly faces that gloomed dark against the twilight, and leered down at them from the high bank and the edges of the wood.
Sounds more like the huorins (sp?) thoses ents that are becoming trees or trees becoming ents. Also, they could be some of the black hearted ents/trees that Fangorn talks about