When the cat is at Vietnam...

... the mice will come in work late.

... some mice will not come into work at all.

... the mice will eat late breakfast.

... the mice will eat early lunch.

... the mice will have two-hour lunches.

... the mice will have one-hour intervals between meals.

... the mice will "program" their Pokédex.

... the mice will "design" their Friendster layout.

... the mice will go home one or two hours earlier than usual.

... the mice will be noisy inside the lab.

... the mice will surf the Internet the whole day.

... the mice will consume each bit of bandwidth they could have.

... the mice will do small work.

Or the best,
... the mice will not do any work at all!