Space vermin are rodents normally found on stations throughout the galaxy. They come in aboard tradeships and survive by eating garbage that careless peeps drop on the ground after a quick visit to the Dine-O-Mat or shop, even if there is a litter bin nearby. As soon as there is something to eat, they scurry up through the deck plating to enjoy their feast of food and toy wrappers.
They cause no outward stress to other peeps. As they are just another form of life, most individuals will actually try to engage them in conversation. However, being only interested in sinking their over-large teeth into more garbage, they are not very good conversationalists. What they are good at, however, is transmitting diseases.
Any peep that converses with vermin will get sick. This is a fact of life. The question then becomes: what illness will befall them? It is a chance, really, that peeps who interact with vermin will end up with something as treatable as the Common Cold, or else be struck down with the dreaded Space Plague.
There are only two ways to rid oneself of these pesky rodents. The first is to ensure that the station is kept clean and free of rubbish. Enough litter bins around restaurants and shopping malls, and peeps will get the hint and make sure to deposit their refuse for recycling. Without any garbage to eat, the vermin will simply vanish back into the hull between decks. Out of sight, out of mind.
The second way of dealing with rodents is security columns. As soon as vermin enter their firing range, they will unleash a brief volley that leaves them as ex-vermin. While this sets off a brief security alarm, all that is left to deal with is a rodent carcass that is just as readily recyclable as any other piece of trash.
As expected however this will freak out the peeps a little.