About placing humanity (or something else) in a category of its own, that depends on how the categorization is made, and it could be done in any way, so such a categorization of humanity does not really help, and can be deceptive to think it is the only one or the best one.
I also think that "intelligence" would not be simply defined by higher vs lower; it is more complicated because of different kind of intelligence and more subclassifications of those too, and then there is the difference of e.g. speed vs knowledge vs etc. There is a sense to identify the intelligence of kind of animals (and of the same kind of animals, e.g. human), but if you merely say it is higher or lower then it is imprecise.
This article also mentions colours, such as red colours. (And other things that you can also feel.) But, not all kind of animal can see all of the colours; some can see some colours that humans does not see but also does not see some that humans does see. Humans can see three colours, but some animals might see four colours. (And, some people also are partially or fully colour blind.)
I had also read in a book once, they said, they are sure that insects have feelings but is not sure about emotions. Well, my guess is probably they do; but, it would be a mistake to think that having emotion would necessarily mean that it is like humans emotions; it can be difference.
Nevertheless, many things that people have said are only for humans and are not what other kind of animals are. In many cases, I think they are wrong (and may even apply for some kind of plants, etc); "conscious" is not the only thing. However, there are also differences (including differences in the details of the things that actually are similar in many ways); and probably some of the differences have been missed as much as many of the similarities have been missed. (There are also differences between individuals, but that is a different thing.)
> And this is important because we need to set rules to protect them either in the lab or in the wild.
You do not need to know exactly how those animals will feel to justify avoiding treating animals badly.
Differences of different kind of animals does not justify to treat them badly.
But, it is good that scientists are actually finally figuring out this stuff scientifically, now. Although I and others had said such things before, that is not the same as doing it scientifically; so now that it can be done scientifically, it will be understood better scientifically, too.