Humansss

If we check in a dictionary, we see that human can be an adjective, as in 'human being' and it can be a noun, as in 'humans are destroying the planet'. In the example above, human is used as a noun.

If we check again in the dictionary, we see that human is a countable noun. In grammar, we know that if we’re talking about all examples of a thing, everywhere, and the thing is countable, then we must add an ‘s’ to the noun:

Mistakes are often made when human is used as a noun modifier, in which case the ‘s’ might be added to the main noun, but not to human:

human as adjective

human as plural countable noun