Well, give that rat/mouse an ultimatum,, let him/her know that if it dosent start pulling its weight around the house and contributing to monetary household items by getting a job, helping put food on the table and paying it’s fair share of the rent that it’s going to have to find some other living situation. Or you could resort to more extreme and inhumane tactics and buy some mouse traps. But I guess that all depends on how you feel about this rodent that’s living with you, are you guy’s close? Homies that go way back? Would you feel bad if you forced him/her to move out and fend for itself? Oh wait, from what you said it sounds like this rodent is a stranger, so in that case just tell the rodent to hit the road and that you’re not going to shelter a rodent that’s a stranger to you that most likely has no plans to show any gratitude for the living space it’s been afforded so far by crashing at your place without being invited. That’s all I got for you. But I’m sure someone else will come along here soon with some better ideas, after all this is the “useless wooden toy banter” section of this message board, so I’m sure your in the right place to get some good advice on what to do and how to move forward, it definitely sounds like it’s a very complex and frustrating predicament that you have found yourself dealing with. Life does have a way of testing one’s resolve from time to time.