In my world the aliens are working alongside human for the sake of their mission. Because the requires them to operate in a zone that is controlled by Humans the aliens have to put up with and be chaperoned by the human military forces in their adventure to find a criminal organization that fleed from their galaxy to take up refugee in the Milkyway. My alien have race have spent the last month's building a friendly relationship with the Humans while at the same time learning skills of communication in order pass along to train a selected group of aliens to travel into the human territory with little repercussions and restraint. Most of the task force that is spearheading the operation with human assistance have never meet a human before however most of alien commander have been working along the human for something now and are use to them. However still experiencing their share of outward moments. The newer alien only have the rumors and superstitions to go one when they first encounter them, which persist throughout their adventure, cause most of the human action don't really enforce otherwise.
Like they believe we can eat and drink anything. Our stomachs can digest solid rock. This comes from the sight of seeing human drink what seem like Acid and other volatile substances......Aka soda, bear, liquor.
Cause we humans have far more muscle mass than they do not to mention a slight height advantage as well. The alien heard rumors like we hunt prey with our bear hands. We fight to the death in order to settle arguments big or small. We humans became the dominant species on earth hunting the dinosaurs to extinction and today we rage war on the dinosaurs closest and last remaining relative...the fierce and might Chicken. The aliens have never seem a chicken be they know the Chicken follows mankind to every planet they colonize bringing each planet in this ending war to the to the frontlines.
The female counterpart of my alien species do not have breast and they are at awe with the so called term "sexuality". As they witness countless times as human males go head over heels to aid, help and assist human female even with minor task and problems. While men of my alien species does nothing of the sort. Since its at eye level most of the alien daemon stare at a humans breast during conversations. This obsession have led some to try an touch them any chance they got, furthermore some of the alien women try these feminine tactic on their male associates to no avail.
Even terms and jokes they use When talking about humans behind their backs like: "Humans don't breathe oxygen, oxygen needs humans in order to survive". "It take 10 humans to screw in a lightbulb but only one to build a planet" and so on.
Their is more but I guess this was a taste. What you think