They develop systems, even complex ones, such as collective intelligence among ant colonies and bee hives, but no other species has developped "intelligence" as an "advantage" on the H.Sapien level. Yet I so no reason for it?
can someone explain?
I'll try, at least how I see it. Humans don't really have much else going for them. We are relatively slow, weak, have no real natural defences like claws or razor sharp teeth, we can't see very well in the dark, our sense of smell is nowhere near as acute as many animals, and to top all that off, we lost a lot of our trees that were our home for so long!
When the African forests shrank and some of our ancestors had to learn to survive in the grasslands some developed a particularly good awareness of their surroundings, the ability to communicate and cooperate as a group, and the mental capacity to use tools and weapons as an extension of their less-than-adequate bodies. These were the ones that survived and passed on these traits. We are here today because our specific type of intelligence was what was needed to survive in the environment our ancestors faced.
As for the insect looking like a leaf to ensure it's survival (slightly off-topic, but since you mentioned it), I think you're looking at it backwards. Rather than looking like a leaf to ensure survival, I'd phrase it that the insect is still surviving because it happens to look like a leaf. Look at insects, there are a lot of different body shapes, colours, sizes, abilities, etc. This suggests that many other different types have been 'experimented' with in the past. Some survive, some don't. Those insects such as our leaf-like friend and those stick-like ones, they survived because of their camouflage advantage. Not really all that complicated when you think about it.
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