If anybody is in any doubt as to the hygiene implications of having mice in an area with food & drink do a quick search on t'interwebs regarding how the critters find their way around...
Wherever there's food, there's gonna be mice.
As long as the kitchen/area has basic hygiene in place (e.g. cleans preparation surfaces, cooks their food properly and will throw out any food supplies that have been eaten off), there's really no need to panic.
Basic pest control (a few well-placed traps, or perhaps a cat) should ensure that the problem doesn't escalate beyond the odd lounge guesting.