Tivk: I require your assistance immediately.
Chief: What's the problem?
Tivk: There is a creature in my quarters.
Chief: What kind of critter? Why didn't ya call security? Sound an alert!
Tivk: It is not an exceptionally large creature. Be careful!
Chief: I don't see no ...
Nok: This is going to be good.
Mukh: And how.
Chief: Are you outta your alien skull?
Tivk: Medically impossible.
Chief: That's a Chinch. It's supposed to be there. It keeps yer digs clean.
Tivk: I do not desire a Terran symbiote. Please dispose of it.
Chief: We use the critters to keep our quarters clean. The little fella won't hurt you.
Mukh: And they look delicious!!
Chief: Don't be eating the symbiote, froggy. Listen here beanpole deal with the critter yourself or let him be. Cuz I ain't hurting a little Chinch. Why don't you ask your entourage here to chase him out?
Tivk: They are being spectacularly unhelpful.
Nok: You thought I'd miss this?
Mukh: Not very likely.
Spacecraft of any tech level eventually become filthy. An enclosed environment with a bunch of humans will soon develop a funk all its own. Most household dust is 70% human skin flakes so dusting is still required. Add to this all the effluvia of eating and living and the many crawlspaces, ventilator shafts and heating ducts and you're talking about a gigantic petrie dish capable of space travel.
Enter the Chinch. The Chinch comes from Chinchilla stock with a minor bit of genetic tweaking to produce a lower birthrate and greater resistance to toxins and radiation. Chinch's retain the heavy fur coats of their wild forebears. Crew can install prefab Chinch houses in various out of the way places and let a family of Chinches lose. The creatures will crawl all over the place eating anything remotely edible. The creatures were bred to have a strong aversion to the taste of plastics and other insulating materials. Chewing through wires is not an issue.
Chinches operate unseen during sleep periods on most ships. Moving around they tireless lap up liquids and eat crumbs while their fur whisks away dust and grime. Back in the Chinch hole the creatures groom each other removing the detritus.
Although they were intended as a cheap maintenance solution many crews name their Chinches, create elaborate Chinch housing and otherwise treat the animals like pampered pets.
Chief: All I'm saying is I'm a graduate of Advanced Tactics school. I completed EVA Ops training with honors. I'm trained on servicing and flying shuttles. You get what I'm driving at here?
Tivk: I am quite sure your training will prove adequate ... It is attacking! Is it venomous?
Chief: Oh fer ... here. I got the big ole alien monster.
Mukh: You going to eat that all by yourself?
Chief: ... I don't understand why you're so freaked out by it. They keep the ship spic and span. They're harmless. Some crew even make pets of them. I think Jenn has one.
Tivk: They have waste. They eliminate like all animals possibly where I may come into contact with said wastes.
Chief: Oh why didn't you say so? No worries.
Chief: Nah. We got little robots programmed to follow them around and clean their crap up.
Tivk: ... I hate you all.