Let’s say your cat has developed a sudden and intense fascination with what’s going on under your sink. You suspect there’s a mouse, although you haven’t seen it.
Do you:
Buy a mousetrap?
or call an exterminator?
(Let’s assume that this is your responsibility…“call the landlord” is not an option.
Ask the cat.
Regards,
Shodan
Option C: Give the cat access to the area under the sink, and let him/her/it figure it out.
Start with a mousetrap and see what happens. If you catch more than one mouse, call an exterminator.
“A” mousetrap is not strictly accurate. You want one along every stretch of baseboard. Meeses hug the walls,partly because they don’t see very well, and partly because it provides some protection.
My house is a little rural, and we have traps constantly set in certain places that we know trap mice. I think the cats actually drag them in and then they escape, so I don’t think an exterminator would help.
I’d give the cats (we have two) a few days to see if they can take care of the problem, then I’d buy an old fashioned spring trap…they’ve never failed us so far.
Whatever you do, don’t give it a cookie
I’d be tempted to put The Killer Elite on to it, but they would most likely tear the kitchen apart trying to get to it. They would certainly scare it out of the house.
I selected set a trap, but honestly I’d just wait a couple of weeks and pull the mouse’s desiccated corpse from the mass of spider webs under there. 
In the past I would set a trap, but lately I call the in-house professionals. They work for food, clean litter and occasional tuna water and aside from the occasional hairball, I find having full-time exterminators well worth the price.
Start by leaving the cabinet door open so the cat can take care of the problem. If that doesn’t work get a trap. A professional exterminator is going to charge a lot of money to set the same trap you can.
Prop up the edge of a cookie tin on a dinner plate, using a bread stick with a bit of peanut butter on it. Set it i n the kitchen, turn off the light and go to bed. Listen for the clank of the tin dropping on the plate, trapping the mouse inside happily noshing on the bread. In the morning, send the kids a block down the street to release the mouse. Repeat daily until the mice have all been deported.
Yep.
Do NOT use poison.
Because I can’t stand the thought of killing a mouse I have live traps. But mice are extremely stupid, so I killed one once with a live trap. How? I washed and put away an unbaited live trap in a big ziplock bag, and two weeks later discovered a dead mouse in - the moron had eaten through the bag the trap was in just to get into it. Sigh. Now I dismantle the traps before putting them away.
Do nothing.
Mice don’t scare me.
I’m not trying to be contrarian just to be a devil’s advocate. I would call an exterminator. I’d like them to find out how the mouse got in. Of course, this would depend on where I was living. If it was an area where this is to be expected, I’d have a cat or two around at all times.
Mice cause property damage. Being rodents, they’re impelled to gnaw lest their incisors grow too long and they starve. They can also infest food with shit, hair and dander, not to mention disease.
One also had the audacity to wake me from my sleep. And the only thing that keeps me from killing people who wake me up for inadequate reasons is the law, so hell no am I going to feel compunction smashing a mouse to jelly. Fucking idiot bastards.
My great-aunt took food up to the attic for the mice regularly so they wouldn’t come downstairs and be a nuisance. At nighttime, when they would be pretty noisy up there, she simply took out her hearing aids. See no evil, hear no evil, kill no fellow creatures.
I’d be inclined to try the option that costs $0.25 before the one that costs $50. Especially since you only have a hunch. The cat could easily be going after the domovoi.
The evil is that they chew on stuff and poop on stuff. They got in my shed and chewed on fishing waders, pool toys, etc.