I have found 2 dead mice in my apartment. How? Why?

February 13, 2014 4:33 PM

In August I found a recently dead mouse in my house that I'm not often at. Today I found a very old dead mouse under the couch. Help me make sense of this.

I'm asking this anonymously because I'd like to have people over at some point again in the future.

I live in NYC, 4th floor walkup. Top apartment. About 9 months ago, I started staying with my new girlfriend a lot, like back at my house once a week to get mail and my house slowly became...disheveled. Some dirty dishes, but I always kept an eye out for food and was pretty good about that but not perfect.

So in August I came home and found a dead mouse in the middle of my living room. I panicked a bit and then cleaned it up. I figured it got under the door (don't love the idea of mice in the hallway but seemed likely) and starved since there was no food around.

But yesterday I moved the couch and found a very old dead mouse underneath.

So now I have a problem. Do I still have mice? I've never seen droppings or anything chewed. Where are they coming in from? Are they still coming in? But most importantly...what are they dying of? Do I have anything to worry about in that regard? They've both been small, but are they maybe small rats?

posted by anonymous to Home & Garden (14 answers total)

Maybe your neighbors put out rat poison and the mice ate that before they got into your apartment?
posted by Jacqueline at 4:38 PM on February 13, 2014 [3 favorites]

You may have another dead mouse in the apartment. You left your apartment free and clear for some mice nine months ago, but you might not have left out enough each week for the mice to live on so they starved to death. If the one behind the couch is very old, it might have died first. The first you found died last.
posted by parmanparman at 4:39 PM on February 13, 2014

I'd also guess that one of your neighbors put out rodent poison and the mice happened to die in your apartment. If you had an infestation, you would have noticed many of the signs: droppings, holes chewed in food containers, urine spots, etc.
posted by quince at 4:44 PM on February 13, 2014

As for how they got in, your apartment is not actually a hermetically sealed box that only opens at the doors and windows. Closets, pantries, cabinets, storage and crawl spaces, etc., are often incompletely sealed and mice only need a very tiny opening to squeeze in and out from between the walls, from the basements, or from the ceilings. I won't say it's no big deal, because ew, but it is very common. You need to check all these types of places if you want to be sure to prevent future intrusions - I kind of doubt they are coming in only under the door. For essentially this same reason, I don't think it has much to do with you spending a lot of time at someone else's house - they could very likely get in at night with little interference regardless.

As for how they died, who knows. I think Jacqueline's guess is as good as anything else we could come up with from a distance. Why do you assume they're small rats instead of mice? Why does it matter?
posted by Joey Buttafoucault at 4:47 PM on February 13, 2014 [4 favorites]

Having mice is not a contagious illness that should keep visitors away. Old buildings often have them living in the walls, and visiting any apartment that offers sustenance in a cat-free setting.
posted by zadcat at 4:58 PM on February 13, 2014 [1 favorite]

Mice are pretty intrepid! I once saw one in the hallway of my 19th floor apartment! and on the 4th floor in college residence I heard mice in the walls nightly. And I grew up in a wood house in the wilderness and mice were just a thing that happened.

They can get in any hole about the size of a dime, so truly mouse proofing your apartment is pretty hard.

If you're not seeing droppings you probably don't have a mouse problem, keep doing what you're doing with your food and any mice you see are probably just occasional interlopers.

I'm with everyone else, I bet they were poisoned and just went to your quiet apartment to relax and died.
posted by euphoria066 at 5:03 PM on February 13, 2014

Nthing someone else in your building put out rat poison, and they are coming to your apartment to die.

As for how they're getting in, there is a hole somewhere. It would be a very unusual prewar Manhattan walk-up apartment that did not have holes mice could squeeze through.

I had mouse houseguests at about half the NYC apartments I ever lived in, and most offices I ever worked in, especially if there was a breakroom or kitchen with snacks.

This is really not something to worry about. Mice exist, and since you're never there, they're not hurting you at all. Just clean them up when you find them.
posted by Sara C. at 5:07 PM on February 13, 2014

Our neighbors in a different building had bad mice infestation. The rodenticide used basically made the mice so ravenously dehydrated that they were desperate to find water, but ultimately died of dehydration. Shortly after that building was treated, after a particularly rainy day, we found a wet dead mouse in the basement and then a week or so later, another dead one. The wet mouse pretty much cemented to us that we weren't a mouse haven, they were coming in looking.

We have two cats too, admittedly one of them is indifferent and useless but the other is a wannabe indoor tomcat. So, for a mouse to try a house with cats, we figured it was desperation. We had bait boxes put in our unit and haven't seen them since.

A couple things to note -- the exterminator looked at our house and said it was sealed up really well, but that doesn't mean mice can't get in. All they need is something the size of a dime to make entry. He also said that most houses have mice - you just never see them. He also said that most multi-family dwellings absolutely have mice too, and it's throughout the building. Cabling, piping, small gaps in the construction all allow for them to move throughout.

Hardware stores sell the bait boxes - not commercial grade, but they work. If it makes you feel better, pick up a pack and put them out. And as always, just make sure your food stuffs are wrapped/contained well.
posted by jerseygirl at 5:09 PM on February 13, 2014

I find dead mice occasionally in various places in my country house. Mice die. They don't have the good manners to go outside to do it. It's rare they die in the middle of a floor, but not unheard of by any means. As far as being ashamed of having mice, I bet there are few dwellings anywhere that do not have mice.
posted by Camofrog at 5:58 PM on February 13, 2014 [2 favorites]

I have found 2 dead mice in my apartment. How? Why?

Pretty much because of this:

I live in NYC, 4th floor walkup.

Be glad that's the only thing you've found, man. Seriously. I'm shocked you've seen so few vermin in your place that two dead mice make you feel like you can't have anybody over to your apartment. In all of the apartments that my friends and I ever lived in, all over the city, I can only recall two where there was never an appearance of a mouse, or a roach, or a rat. These were expensive buildings, crappy buildings, walkups, elevator buildings, new, old, Manhattan, Brooklyn, Queens.

It's part of living in the city. It's just an issue that's everywhere. Mice get in through cracks in the walls, openings, holes, etc. And they should be able to get back out the same way they got in. So for that reason I agree with the people who said someone in your building is laying out mouse poison and they probably just happened to die in your place. If you want to figure out how they got in I would suggest checking around your baseboards, around your doors, windows, toilets, sinks, cupboards, and behind your appliances (fridge, stove, etc.) for openings.
posted by cairdeas at 7:37 PM on February 13, 2014 [2 favorites]

Somebody probably put out poison bait. Many common poisons (e.g. warfarin) cause animals to become very thirsty as they die, and the mice were probably looking for water.
posted by Kadin2048 at 8:44 PM on February 13, 2014 [1 favorite]

Just seconding what everyone else said- mice are everywhere and sometimes they die. Keep food sealed and keep the place clean and you should be okay, especially if your neighbors are being more proactive and poisoning or trapping them.

Do you have a metal radiator in your apartment for heat? There's often a hole where the steam pipe enters from the wall or floor that mice might be able to get through, or other vents. Another source is the hole where the gas line runs to your stove. Another could be the hole for plumbing under your sink.
posted by Wretch729 at 7:49 AM on February 14, 2014

Yeah, you live in NYC. There are mice in every building. If you've only found dead mice and no other signs of an infestation, they probably ate poison elsewhere and came in through some means and then just died in your apartment.

NYC mice anecdote: We had mice come into our place through improperly sealed holes around the water lines behind our dishwasher. The super put a bunch of steel wool around the lines. No more mice. I was relieved, but our cats were pretty bummed that their prey stopped showing up.
posted by bedhead at 8:17 AM on February 14, 2014 [1 favorite]

This wouldn't happen to be on 79th street, would it?
I had a 4th floor walk up, would catch and release a mouse every few months. One night I caught a mouse while working from home, so I left the mouse in a box with some food and water while I wrapped up work. Two hours later, I checked the box, and the mouse was dead.


So yes to what was said before: you have a neighbor who is poisoning the mice, they are coming in to your apartment to die. If they lived in your apartment, you'd find droppings.
posted by ®@ at 9:00 AM on February 14, 2014