Annoying habits: Gnaws through drywall, nibbles on wiring, and pops out of mouse holes, alarming fauna of the Homo sapiens kind.
What you need to know: Can climb, jump, swim, squeeze through dime-size openings, and live on crumbs. Mainly nocturnal. Scoots around the edges of a room, using its whiskers to steer. Sexually matures at 6 to 10 weeks, bearing a litter about 20 days after mating. You do the math.
What you need to do: Sprinkle baby powder on the floor to track your prey. Plug any hole bigger than a quarter of an inch with steel wool or hardware cloth (available at hardware stores). Make sure there's no space under doors. Buy a cat.
If that doesn't work: Set snap traps with a smear of peanut butter or Nutella. Terminix, the pest-control company, recommends traps with extra-wide triggers (available at hardware stores). Place traps two at a time―pairs work better than singles―perpendicular to a wall, with the trigger edge closest to the wall. (Glue boards will do, but who wants to come home to a squeaking Mickey?)
2 of 6Greg Clarke
Uninvited Guest: Raccoon
Habitat: Common throughout most of the United States. Prefers wooded and waterfront property and access to prepared foods.
Annoying habits: Empties the garbage and plays kick the can. Enjoys taking a dip and snacking on fish. Stages nocturnal raids, using its dexterous paws to rip into bags of Fritos.
What you need to know: Likes to nest in chimneys and attics. Strong, smart, and omnivorous. Can be a carrier of rabies.
What you need to do: Call a contractor to install a mesh chimney cap (look under Chimney Builders and Repairs in the Yellow Pages). Trim tree limbs near the house. Keep pet food indoors. Put some ammonia-soaked newspapers at the bottoms of garbage cans and cayenne on top of the garbage. Tie down lids with rope.
If that doesn't work: Trap and deport the invaders. Consult your state's Department of Natural Resources for rules on releasing raccoons. For the names of wildlife-control operators who can get rid of the animal for you, look up Animal Removal Services in the Yellow Pages or go to icwdm.org.
3 of 6Greg Clarke
Uninvited Guest: Deer
Habitat: Most of the United States, from woodlands to suburbia (sometimes even downtown).
Annoying habits: Devours tulip buds just as they're ready to bloom. Chews hedges to a nub. Rubs the bark off some trees. Tramples flower beds. Plays chicken on roads and highways.
What you need to know: Can be a host of the tick that carries Lyme disease. May be able to leap over eight-foot fences. Usually dines at nightfall or just before dawn, treating your yard as a salad bar.
What you need to do: Plant things that deer don't like. Find examples at highcountrygardens.com, or contact your local Cooperative Extension office to check the palates of your local herd. Safe repellents (available at garden centers) include Deer Stopper and Bobbex. Or try scarecrow sprinklers with motion detectors that trigger alarming bursts of water.
If that doesn't work: The best offense is a good fence. Count on erecting one that's more than eight feet high. Or install two five-footers about four feet apart from each other.
4 of 6Greg Clarke
Uninvited Guest: Squirrel
Habitat: Got trees? Actually, any pasture, park, or yard will do.
Annoying habits: Embarks on unnecessarily raucous tree chases during mating season. May see your garden as a good place to dig and your house as a superdeluxe tree with nesting possibilities. Astute at finding holes and cracks in roofing and eaves.
What you need to know: Creative thinkers; attic lovers. Highly territorial; potentially destructive.
What you need to do: Trim tree limbs growing close to the house, secure loose shingles, and seal holes with heavy wire mesh. Have a contractor install a mesh chimney cap (look up Chimney Builders and Repairs in the Yellow Pages). Deploy dogs as patrolling agents.
If that doesn't work: If they're nesting in your attic, turn up the volume on an obnoxious radio or TV talk show―squirrels hate shouting matches. Scrub down surfaces with ammonia and scatter mothballs. Seal all holes. Hire a contractor to install metal flashing around eaves. For pros who capture culprits and keep them out, go to icwdm.org.
5 of 6Greg Clarke
Uninvited Guest: Bat
Habitat: Trees and buildings throughout much of the United States.
Annoying habits: Flies through open windows, touching off panic and coiffure-related concerns.
What you need to know: Flies by night in search of water (ponds, swimming pools) and insect congregations (around porch lights). Can carry rabies. For bug control, however, bats are a godsend, devouring mosquitoes and other insects by the bucketful.
What you need to do: Make sure all windows, including little ones in the attic, have screens. Seal holes and crevices larger than a silver dollar everywhere around the roof.
If that doesn't work: Confine an errant bat by closing all doors and opening a window to let it escape. Or sneak up on it with an empty coffee can or bucket, clap the can over the bat, slide the can onto a piece of cardboard, and let the bat loose outdoors. For names of professionals who can remove bats, go to icwdm.org.
6 of 6Greg Clarke
Uninvited Guest: Chipmunk
Habitat: Woody, brushy areas.
Annoying habits: Dismantles potted plants and damages bushes by burrowing under roots. Helps itself to flower bulbs and seedlings.
What you need to know: Constructs tunnels up to 30 feet long. Goes underground in winter, living off cached food. Busy, busy, busy in early morning and late afternoon, scouring for snacks and unearthing rock gardens and geraniums.
What you need to do: Keep pet food indoors. Stuff hardware cloth into gaps in the foundation of the house. Trim ground-cover plants so that the offenders have fewer places to hide. Experiment with chipmunk repellents, such as those made by Deer Stopper.
If that doesn't work: Bait live-catch traps with peanut butter, raisins, or granola. Brands of traps include Tomahawk (livetrap.com) and Havahart (havahart.com). For pros who can capture and relocate creatures, go to icwdm.org.