What traps are effective for rodents in winter?

It is tempting to assume a newer, more expensive device must work better, but the evidence runs the other way. UC Statewide IPM's guidance on the house mouse is unambiguous that trapping is "the safest and most effective method for controlling rats and mice in and around homes, garages, and other structures." A snap trap kills quickly, holds the animal for disposal, and tells you exactly where the activity is happening -- information a bait station or a repeller cannot give you.

Glue boards look like a cleaner, less violent option, but the research doesn't support that either. Adult rodents can often detect and avoid the glue outright, so what a glue board actually tends to catch is inexperienced juveniles, not the breeding adults driving the problem. Dust, cold, and moisture also degrade the adhesive over a winter, so a board set in October may be useless by December even if nothing has visibly changed.

House mice seldom venture more than about 30 feet from their nest and food supply, which is why UC IPM's practical advice is to space traps no more than roughly 10 feet apart along the walls, baseboards, and corners where you've already seen droppings or grease marks -- and to use enough of them that the job is short and decisive rather than a slow trickle of one catch a week.

Rats add a wrinkle mice don't: neophobia, an instinctive avoidance of anything new in their environment. UC ANR's guidance on managing rats with snap traps is to leave the trap unset and pre-baited in place for several days before setting it live. Skip that step and you will likely catch only younger, less cautious rats while the established, breeding adults keep clear of it -- which looks like success but isn't.

Size matters too, and it isn't a formality: a mouse trap's trigger and spring are calibrated for a mouse's weight, and a rat will either avoid it or spring it without being caught. Use a rat-sized trap for rat sign, a mouse-sized trap for mouse sign.

Rodenticide bait is a separate product class from a trap, and it belongs outdoors in tamper-resistant stations under EPA's consumer-product restrictions -- not loose indoors, where pets and children can reach it and where a poisoned rodent can die inside a wall. This page names the product class and routes you to the label; it does not give dosing or placement instructions, because that is exactly what the label is for.

Live-catch traps have a genuine appeal -- nobody has to see a dead animal -- but the honest tradeoff is worth naming. A live, stressed rodent in a trap may urinate or defecate, and New York State Health's hantavirus guidance is specific that snap traps are preferred over glue or live traps partly for this reason: hantavirus spreads through airborne particles from disturbed rodent urine and droppings, and a distressed animal produces more of both. A quick, clean kill is not the callous option here; it is the one with a smaller aerosol footprint.

DIY trapping is squarely the right first move for an active, localized problem -- droppings in one or two rooms, a runway along one wall, a handful of catches over a week or two. It stops being the right tool once activity is heavy or spread across multiple rooms, once you suspect an in-wall or attic population you can't reach with a trap line, or once you simply don't want to handle carcasses, disposal, or the hantavirus precautions that come with cleanup. That is a fundamentally different job -- inspection to find the source and exclusion to close it -- and it's where a pro's inspection earns its keep rather than another round of traps.