You can see it concretely? Why do you need a long way to understand it? They are just trying to SURVIVE. Because they are programmed as some living things which is just trying to survive.
We are all programmed to survive, and if there is one universal meaning of life it is this.
I just suggest you seriously explore the internet as to what we know currently about animal intelligence and behaviour and what we are discovering so as to expand any old beliefs. Why is it slow progress? Because, as might be expected, observing the behaviour of any particular non-human species takes time and effort, given that observing any in captivity is hardly likely to reflect their reality. Even doing so for those human societies that might appear 'primitive' to an 'enlightened' one might produce much the same - and perhaps leading them to being wiped out.
There are just too many examples of various non-human species using intelligence - from squirrels learning how to overcome various obstacles to food (why do so when food might be more easily obtainable elsewhere?), to whales cooperating in various ways so as to consume their prey, to great apes understanding humour, to so many species coordinating their activities during a hunt, to so many species that remember vast numbers of locations as to food resources, as to our canine friends that seem to show empathy (personally experienced), and as to a few species that can learn a language not native to that species - a sign or symbolic language perhaps for chimpanzees or bonobos, or even dogs.
These all negate the notion that animals just react from instinct - unless so many have the same instincts as humans.
PS And I missed out the communications between various species that we have still to decode so as to understand more about any societies that do form. Why form societies if this doesn't also perhaps imply intelligence?