How to Tell If There's a Mouse in Your House

You have just settled down in bed and are twenty five minutes into Letterman when you hear it: a mild scratching overhead, accompanied by a squeak here and a squeal there. You assume that it is the end making strange sounds, or perhaps the home is just settling. Maybe the sounds are merely the result of an overactive imagination. You hope!

Naturally, you can't get around the obvious conclusion - you have company. When it is a bird, a bat, a squirrel, or an entire family of mice, there is something up there. Given that you have had recurrent rodent problems, the latter option is probably the safest bet.

But how can you be sure what sort of animal you are dealing with - assuming that you have unwelcome visitors at all? Before you can evict them, you will need to know who"they" are.

Above all else, your first step is to inspect your home for signs of mice. Various issues call for different solutions; if your customers are actually squirrels instead of mice, you will need to come up with a different strategy.

When canvassing your home, keep an eye out for these seven telltale signs:

1. Droppings and urine. Mouse droppings resemble a grain of rice; they are approximately the same size, but are black in color. Mice won't generally travel across open spaces, which means you are more likely to find droppings along walls, pipes, and beams, as well as in storage areas and alongside objects. "Urine pillars" are less common; they consist of mounds of grease, urine, and grime. You can also use a blacklight to discover individual urine droppings.

2. Chew marks. Search for tooth marks and wood shavings (similar in consistency to sawdust) around doors, baseboards, and cabinets. Marks on food containers can also be a clue that you have company.

3. Grease marks. When traveling alongside pipes, beams, and walls, mice may leave greasy smear marks, as dirt and oil from their fur rubs off on the surfaces.

4. Tracks. Footprints and tail marks dirty, dusty, or muddy surfaces can indicate activity. If you suspect that mice have taken up residence in an otherwise impeccably clean area of your home, lay down a sprinkling of talc to catch them in the act.

5. Nests. Mice construct nests of shredded paper and similar debris; assess attics, basements, garages, storage areas, closets, and other dark, enclosed places for nests or"stolen" materials.

6. Sounds. You are more likely to hear squeaks and squawks at night, once the house is silent and your guests are active.

7. Sightings. It is not unusual to find mice throughout the day; although they are largely nocturnal, they do move about in daylight.

Now that you are certain that you are dealing with mice, it is time to start strategizing. Your plan of attack will actually arrive in three phases: first you want to clean up the messes you discovered; next, you have to trap and release your undesirable visitors; and finally, you're mouse-proof your home so that they can't get back (and would not want to, even if they could!).