Thanks to @Conifold I found the answer quite easily
If anyone is inclined to deny that we can believe in the existence of
facts like this whose exact nature we cannot possibly conceive, he
should reflect that in contemplating the bats we are in much the same
position that intelligent bats or Martians7 would occupy if they tried
to form a conception of what it was like to be us. The structure of
their own minds might make it impossible for them to succeed, but we
know they would be wrong to conclude that there is not anything
precise that it is like to be us: that only certain general types of
mental state could be ascribed to us (perhaps perception and appetite
would be concepts common to us both; perhaps not). We know they would
be wrong to draw such a skeptical conclusion because we know what it
is like to be us. And we know that while it includes an enormous
amount of variation and complexity, and while we do not possess the
vocabulary to describe it adequately, its subjective character is
highly specific, and in some respects describable in terms that can be
understood only by creatures like us. The fact that we cannot expect
ever to accommodate in our language a detailed description of Martian
or bat phenomenology should not lead us to dismiss as meaningless the
claim that bats and Martians have experiences fully comparable in
richness of detail to our own. It would be fine if someone were to
develop concepts and a theory that enabled us to think about those
things; but such an understanding may be permanently denied to us by
the limits of our nature. And to deny the reality or logical
significance of what we can never describe or understand is the
crudest form of cognitive dissonance.
Bat consciousnesses is still part of reality, which suggests that "what causes consciousness" does not reduce to "what causes human consciousness".
The quotation is from Nagel's What Is It Like to Be a Bat?
