@user535733 I'm thinking... Tactics? The point is: Armed humans can lay waste to a normal forest cause animals aren't organized. They will act in a responsive way to the intruders in their habitat. These animals are organized - though the humans still have weapons and tools to suppress them. I'm interested in how the animals will deal with the humans and their tools, which abilites can they benefit from to find the best method to stop them from getting further into the woods.

While it's definitely not a duplicate, some of the discussion in answers and comments to my old question How can humans coexist with an intelligent carnivorous species? may still be of interest.

@aCVn I'm certainly checking that out. Thanks for bringing it up.

The US lost the Vietnam conflict to people who weren't wearing shoes... where 'laying waste to a forest' proved difficult, even with B-52s

Is your story set on humans entering the forest? If I had to deal with a forest full of aggressive animals, I might just burn it to the ground. Humans have done this for centuries, and still do, to clear land for farming. Your animals might need a team of firefighters.

@craq It will feature humans entering at some point. But the humans want what's inside the forest. They might start fires but they shouldn't, cause they would end up jeopardizing what they're there for. I'll add this to the question to clarify. Thanks for the input.

@craq - need foresters, people who do controlled burns. I wouldn't be relying on the lack of stupidity in humans to save me.

to be clear what level of technology are the humans at, spears and bows or guns and bulldozers?

How long does a foray into the forest take? Forest defenders might have a hard time responding to an hour-long smash-and-grab, but they'll have a much greater home turf advantage if it's a day-long trek each way into and out of the forest. If the invaders need to stay overnight in hostile territory, many more options become available to the defenders.

A couple of short stories that might give you some ideas: Leiningen Versus the Ants and Brain Wave. While neither of them deal with your scenario, the idea of animals either gaining intelligence or battling humans is in them.

12 hours? That changes everything. Are insects part of the equation? I also need to know just how bad the humans want it, or what it is. - (On a side note, receiving more than one answer per hour for the first 11 hours, is not a good sign.)

Related question. In that question, there's magic and you can train the animals, but they may not be extra intelligent like they are in this question. Still, I had fun with my answer.

In the real world, our intelligence just barely compensates for the many advantages animals have over us: strength, speed, vision, hearing, smell, venom, claws, … Since you propose removing that difference, you’re putting us on the endangered species list.

I read a scifi novel once where all the native life on this distant planet was telepathic (or otherwise able to communicate) and mutated heavily to counterattack on the humans. When a human left the settlement the mutations quickly wore off when he got further away. Perhaps it could be an interesting inspiration. Unfortunately I cannot remember its name.

Have you read The Jungle Books by Kipling? In particular, "Letting in the Jungle"‌​?

Four legs good, two legs bad?