Got Mice?
My daughter, who works in a hardware store, has been passing on to customers some of the techniques I have developed in 30+ years of mouse catching experience.  She says the hints are very well received, so I have decided to express my advice here, in hopes it may prove useful to others.

Dealing with mice in the house is a nasty business, but living with them is even nastier.  Not only do they carry diseases, but they poop wherever they want to with no sense of responsibility whatsoever.  Plus, they like to (and indeed must) chew on things, causing potential structural damage and problems with plastic pipes and electrical wires.  They also bring in smaller vermin when they come.  So, we do what we must. 

Subjects covered here

Two Techniques
About Mice
How to Know You Have Mice
About Poisons
    About Traps
Baiting a Trap
Setting a Wood and Wire Trap
Placing a Trap
    Disposing of the Body
Unsetting a Trap
Live Catches
Preventing Their Return

Two Techniques

There are two things I do differently than most other people. 
  1. I like to place a conventional trap inside a paper bag, such as a lunch bag or fast food bag.  Pick one big enough to allow the spring-loaded hammer (Sorry, but that's what it's called.) to swing over when the trap if triggered.  Place the bag with its narrow side down so the hammer has headroom.

    The bag (usually) shields us from seeing the victim until we have steeled our nerves in preparation for looking inside.  It also provides a sanitary alternative for those who wish to dispose of the remains, trap and all, without touching it.

    I write MOUSETRAP on the side of the bag, so others in the household know why it's there.

  2. I put out a "mouse detector," a scrap of paper with a few circles on it, labeled to let others know why it's there.  Put the detector in a place where mice might find it, and put a bit of dry food in each circle.  Keep the bits small - we want to detect 'em, not nourish 'em! 

    If, later, you see empty circles, steel yourself and check the trap.  In any case, you know you have something in the house, and you know what it likes.  It, in turn, now knows where to look for more.  Free samples do bring in the customers!

If you use a trap of any kind, check it several times a day for results.  When a mouse is caught, I dispose of it promptly, refill the detector, and reset the trap.  When it seems all the mice are gone, I may unset the trap, but leave the mouse detector. 

If you can figure out where they are getting in, and block it, you may not need to revisit this page.  Until they find another way in.

That covers the my contributions to the subject.  If you need more details, keep reading or search the internet for discussions on the subject.

About Mice

Although we have had mice at various times of the year, the onset of cold weather tends to drive them indoors.  How they get in I'm not sure, but keep in mind a tiny opening, so small or obscure we might overlook it, is as good as a grand entrance to them.

Male or female?  If you really want to know, check for the mammary glands.  If I (ahem) told you where to look, you wouldn't believe me.  If you have to know, you can search for mouse mammary glands in the Internet. 

How you can know if you have mice.

One of the more obvious signs is their droppings, which look like black caraway seeds with fuzzy ends.  Real caraway seeds don't have fuzzy ends. 

Noises in the walls and ceilings are another sign, as are sounds of things getting knocked over in the cupboards. 

If we think we might have mice, but don't want to commit to checking a trap every few hours, we may just put out a "mouse detector."

About Poisons

Poison has its advantages.  You put it out per package directions, the mice find it, eat it, die shortly thereafter, and you don't have to think about it again. 

Except I do think about it again.  Those little bodies, they have to fall somewhere, but where?  And what happens to the remains?  And when?  And for how long?  I've been told the poison makes them go in search of water, which they usually have to leave the house to find.  But there's often water in the drip pan under a frostless refrigerator, so some may end up there.

About Traps

Most traps fall into one of three categories, live-catch, sticky traps, and the kind designed to kill.  All of them should be checked regularly, each for its own reason. 

I make it my policy to check each trap two or three times a day.  If I can't check a trap at least daily, I don't leave it set.  If you've caught something, but you put off checking for too long, disgusting things start to happen.  I'll explain what that means for each kind of trap.

Live-catch traps

An Unfortunate Experience with a Plastic Trap
First of all, in my defense, I wish to state that I sincerely thought the mouse was dead.  That is, after all, what the package claimed, "kills mice," and that's exactly what I wanted.  No doubt they can and do, but any trap can fail to live up to its reputation from time to time.

These new plastic Tomcat® brand snap traps looked promising: easy to set without endangering ones fingers, easy to bait, depending only upon the mouse's weight to set it off, and not on its efforts to pull a bait free of the catch. 

Even as I set the trap, I knew how I wanted to deal with the body: Having read that an occasional dead squirrel was beneficial to a septic tank, I figured a dead mouse was at least a step in the right direction, and easier to flush. 

A few days after I set the trap we heard a sudden commotion in the kitchen, and I went to deal with it.  The mouse, a brown one, was apparently conscious long enough to pull the trap most of the way out of the brown paper bag I'd placed it in, but by the time I arrived, it was only twitching, and even that stopped after a short time.

Triumphantly, I proceeded to the bathroom, raised the seat, removed the trap from the bag and squeezed it open over the bowl.

The mouse must has been unconscious, for the cold water revived it, and it immediately began treading water and looking for a way to climb to safety.  It had made at least two full circuits of the bowl before I decided that any attempt at reconciliation between us would, at this point, be doomed to failure.  I hit the flush lever.

Sensing the new situation, the mouse switched to full-bore swimming, in a valiant attempt to escape the clutches of the watery vortex that slowly and inexorably dragged it down to the darkness below.

It was a close contest, but as the water settled, I began to breathe easier.  What was done was done, and there was no other action I could have taken under the circumstances.  And it was, after all, just a mouse.

Suddenly, a sodden form emerged from the depths and shot to the surface, gasping for air and swimming for its life.  In panic, I hit the lever again, and watched in horror as again it slowly lost ground to the rushing waters and disappeared from sight.

Again I hit the lever, and again, and again, my eyes riveted to the spot where I last saw it.  At last, I stopped, and stood, and watched for any sign of its return, but it was not to be.  I can only hope that death came swiftly and mercifully.

Live-catch traps are usually safe and easy to set,  but so are most of the
plastic killing traps, although I've had mixed results with them.  (See box, right) 

One advantage of a live catch trap may be that the vermin on the mouse may stay on the mouse, and not go in search of other hosts as the body cools.  After all, they say it wasn't so much the rats that spread the black plague, but their fleas after the rats were killed.

But I have avoided Live-catch traps ever since an incident at work:  The mouse I found in the trap early that Monday morning had been confined in a space that was not much bigger than he was, probably for most of a weekend.  I carried the trap, mouse and all, to the far side of the parking lot, where an area covered with grass and leaves could provide some cover, and dumped him out onto the ground, expecting him to run away.  Instead, he just huddled there, wet and covered with filth, a mouse utterly broken in spirit.  I could not think what to do to let him know he was free, and the needs of the business weighed heavily upon me, so I left him there and did not look back. 

If you go with a live-catch trap, please check it regularly.

Sticky Traps

There are effective for small mice who may not trigger other traps, but are probably the least humane, as the mouse may have to damage itself in an attempt to escape.  Check it regularly to prevent this.

Personally, I would only use one as a last resort, if other traps don't work.

Traps designed to kill

While I've never seen proof that a mouse released outdoors will find his way back into the same house, why take a chance?

I still like the old-fashioned wood and metal type with the spring-loaded wire hammer that swings over to wack whatever is on the bait side of the trap, be it mouse or thumb.

There are some similar traps that have a plastic trigger that looks like a piece of yellow Swiss cheese.  These are easier to set, but only pressure straight down on the trigger will set them off.  I've had mice steal the bait without tripping the trap.  Use a twist-tie to attach the bait securely.

The old wood and metal kind are tricky to set, but they can be set off by almost any movement of the trigger.  I have written some setting instructions below.

Baiting a trap

This should be done before the trap is set.

The bait should be something the mouse likes.  Popcorn seems to work pretty well, sometimes with a little peanut butter for the aroma.  The year the mice started to get into the Easter candy, half a jelly bean, moistened and wrung onto the catch, worked well for several mice.  I have never had much success with cheese.

If the bait is something solid, like a peanut, it is important for the bait to be held tightly on the catch, so the mouse has to work to get it free.  The wood-and-metal type have a place on the catch with teeth to hold the bait securely.  The plastic-Swiss-cheese type does not, use a twist tie.  I have had some success using something soft, like a Craisin®.  I roll it between thumb and finger until it's thin, poke it through one of the holes in the trigger, and mush it over on both sides.

If you use something perishable, like peanut butter, change it from time to time.  Mice prefer fresh food.

How to Set a Wood and Metal Trap (Like the One Shown Above)

If the trap is new, remove and discard the thin wire staple that prevents the catch lever from swinging around in transit.  The trick to setting a trap without self-injury is never to put your fingers on the bait side of the top of the base when the hammer is under tension.
  1. Hold the trap on the palm of your hand with the catch lever end near your wrist.  Make sure the catch lever is out of the way for the next step. 
  2. With your other hand, lift the hammer and swing it over to the other side of the trap.  Hold it down with the thumb of the hand supporting the trap. 
  3. Use your free hand to bring the catch lever over the hammer and hook it onto the part of the catch designed to just barely hold it.  You may have to hold it there for the next step.
  4. SLOWLY raise your thumb to allow the hammer to rise until one of two things happens:
    1. The hammer pushes the catch lever up, but the catch lever doesn't catch and hold on the catch.  Push the hammer back down and try again.
    2. The hammer pushes the catch lever up and it catches and holds on the catch.  Whew!
  5. Now that the trap is set don't touch the top of the trap.  Carefully remove your thumb from the hammer.
  6. If you are going to put the trap in a paper bag, push on the edge of the trap to rotate it on your palm so the bait end will be nearer the open end of the bag.
  7. Pushing only on the edge of the trap, gently slide the trap off your hand onto the place you want it.  (Think "pizza peel".)

Placing a trap

Place the trap in an area mice are known to visit, but still easy for you to get to.  I find if it's in an area easy to get to, I will check it more often.  If the mouse has been on the counter-top, place the trap there. 

Disposing of the Body

Great fleas have little fleas upon their backs to bite 'em, And little fleas have lesser fleas, and so ad infinitum.   – Augustus De Morgan
Some may wish to dispose of the mouse, trap and all, in the garbage.  I'd say do it in the outside container, not in the kitchen.  Mice almost certainly have some kind of fleas, lice, or other parasites on them, and where those go when the mouse grows cold I'd rather not contemplate.

Our house has a septic system, and some folks say the "health" of the septic system can be maintained by adding a dead squirrel to the system from time to time.  I figure a mouse can't hurt anything and so I open the trap over the toilet and let 'em drop.

Traps can be reused more than once, if emptied promptly.

Unsetting a Trap

Rather than press on the catch to disarm a set trap, and risk breaking something, I simply pick it up and drop it, bag and all, until it goes off.

Live Catches

Even the metal and wire traps can result in a live catch from time to time.  While I don't mind if a mouse is killed by a trap I set, I haven't tried to bring myself to kill one by hand.  If they're alive and in good shape, I take them outside and let them go.

In addition to the one mentioned in the box above, I've had several live catches.

The first one was caught by one leg.  I took it out to the street and let it go.  It took off for the tall grassy area across the street at a speed that makes me think nothing was broken.

The second one doubled back and ducked into a hole under our concrete front steps.  I've put hardware cloth over the hole since.

I've also driven some to vacant areas and released them there, but that's a bit extreme.

The next live catch I'm going to mark with a marker before I release it locally, so I'll know it again if I see it.

Preventing Their Return

Well, obviously, if I have 30+ years of experience catching mice, I'm not an expert at keeping them out.  But I do know a thing or two.  There is something to be said for not blocking their paths inside the house.