I'm all in favor of searching the stars for alien intelligences. I'm absolutely certain they're out there somewhere, though probably too far away to reach easily. Many of them will be below our level of technological advancement, many others will have never bothered with technology, still others will have obliterated themselves when they became powerful enough (as we're in danger of doing), but I'm sure there will be alien intellignces out there... somewhere.
I'm not sure how likely it is that we'll recognise them when we see them though. Watch science fiction on TV and at the movies where aliens abound, and you'll think that of course we'll recognise them. But why is it that we generally don't recognise the alien intelligences already here on Earth? In fact many of us refuse to even recognise intelligences which are very similar to our own.
Dolphins are very like us, in that they have brains similar to ours -- our brains differ in complexity, size, and how convoluted the cortex is. On many scales, dolphin brains are superior to ours. The only way we smug humans can assume that we are smarter is that we have technology and they don't. But dolphins are well fitted to their world and never needed to develop it, whereas we are weak, awkward, unfit creatures, out of touch with our world, and would quickly die without our technology. Yet most people still consider dolphins inferior.
Anybody who lives with dogs will have many stories of their intelligence, morality, and even their sense of humor, yet many people don't even accept that they have feelings!
What chance is there for accepting truly alien intelligences?
To be honest, there are some who have spent their lives studying the aliens we share this planet with, but their work is not widely known. Irene Pepperberg has spent decades studying the mind of birds, specifically African Grey Parrots, mostly through her associate, Alex, who is an African Grey Parrot. Alex has shown that he can understand abstract concepts like color, shape, and number. In fact Alex is better at counting objects at a glance than any human. Birds are really more alien than you might imagine. We use the wrinkled grey cortex of our brains for thinking. Birds have developed an entirely different part of their brains to do that job. And they are more efficient at it than we are. The constraints of flight mean they need to pack more into a smaller volume, so they test as much smarter than mammals with equivalent brain sizes. Parrots and crows are the intelligent envoys of the bird world.
Then there are even more alien creatures like squid (do you eat kalimari?). They are smart and social. They have a way of communicating that stretches our understanding to the limit. Instead of making noises they ripple colors and patterns along their skin. They are very adept at this and a squid can be displaying one set of colors and patterns to a squid on one side while simultaneously displaying a very different set of colors and patterns to another squid on its other side. I read a while back of a researcher who was studying squid in the wild to see if they have a reliable vocabulary and has found to his delight not only that they do, but that it is very large. Squid and octopus are shellfish, related to the snails in your garden. Octopus have shown many times how intelligent they are, even understanding how to open a bottle to get the contents. An octopus' brain is very weird, and forms a ring around its throat. How alien can you get!
The elephant fish lives in muddy eastern rivers of Africa. It has a large brain and is said to be very intelligent and easy to train, but as far as I know nobody has really studied it much. It "sees" in the murky waters using electrical fields that it generates with specialised muscles down its sides. Imagine that for a moment. It is aware of things all around it at once and is able to integrate the pattern to make sense of it. Another very strange alien living here.
Recent research has shown that even tiny little fruit flies have the rudiments of conscious mind! How long can we remain so blind and refuse to see the alien intelligences all around us? And what hope is there of seeing it when we find it out there among the stars?