Uninvited Guest: Mouse

Habitat: Thrives just about everywhere.

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?)

Tip: Desensitize your prey by baiting a trap but not setting it. After the pesky visitors get used to using the trap as a fast-food joint, put out several others and set them to spring.