You have been asleep since about 1953. It’s 2018 now and there have been a number of social advancements.
Here in 2018, it is rude to misgender others, including those who might look a different from you.
Generations of people, many having long been adults, have grown up watching cartoons and live action shows depicting races of nonhuman and/or partly-human characters. Examples include:
Teenage Mutant Ninja Turtles
These characters are politely referred to with the pronouns in which they use to identify themselves. This means that these characters, along with the Stargate races, should not be referred to as “it,” “thing,” and so forth, which are for inanimate objects and is, therefore, objectifying.
On Stargate, the Wraith refer to themselves with he/him and she/her pronoun sets. Not “it.” Anything else violates the canon source hierarchy (dialogue, visual cues, and end credits).
There is no need other non-binary people and/or characters, by either making all of the aliens non-binary and none of the humans (exoticizing rather than inclusive and normalizing), or by impolite use of the word “it” (objectifying).
In the event a character is non-binary, preferred pronouns are often they/them or other sets of pronouns. Please see this link from Wikipedia on genderqueer identities for examples. Please also see this link from Oxford dictionaries to verify the grammar and history of the use of they/them in the singular.
Also, here in 2018, it is also rude to make up puerile rumors about scifi races in general, such as alleged body odors, nor call them names, such as “thing.” In the ways which matter the most, we are all alike, and we are someones, not somethings.
Welcome to 2018.
A modern scifi reader