As with other cases across the biological spectrum, we're continually astonished when "lower" organisms display the ability to do things we thought were unique to higher ones... especially humans. Yet in this case, we can safely say that all of the macroscopic sensory abilities and behaviors we see have their roots, as well as their parallels, in the microbial kingdoms. Macroscopic behavior is a reflection of microscopic behavior; big things reflect little things.
This fractal arrangement is consistent throughout nature, so much so that it gets glossed over. But even the smallest creatures are not, in the end, so much unlike us. The same, or at least similar, sensory tools are needed to orient, to taste, to "see," on every level.
Microbes, which perhaps seem to be alien creatures, as small as they are, thus share an oft-unrecognized kinship with us. Not only do they colonize us, parasitize us, and coexist with us; each microbe is a legitimate, unseen life carried forth and lived out according to imperatives that, to it, are just as compelling as our own. There is a sensory and molecular awareness within these creatures; and it's to be appreciated, not dismissed.