Keeping Rats and Mice Out of Your Compost

Use a closed bin with a hardware cloth floor, keep meat, dairy and cooked food out, set it well away from the house and turn it often. That stops most rodent problems in compost. An open pile of kitchen scraps against a block wall is the opposite of all four.

Compost is warm, sheltered and full of food, so it draws mice and, in the right spots, Norway rats or pack rats. The New Mexico Department of Health includes compost piles in its plague and hantavirus advice, telling people to keep them far from the house.

Mice and rats eat seeds, grain, fruit and vegetable scraps, all common in a compost pile. A pile that isn't turned stays loose inside and offers nesting room, and decomposition keeps it warm in winter. In the dry Albuquerque climate, a moist compost pile is also a water source.

The state rodent guide notes Norway rats turn up sporadically in larger New Mexico cities and in some farm areas. When they do, they're often tied to a food source like this. Most compost visitors here are house mice, deer mice and pack rats.

Look for these:

• Tunnels or burrow openings in or under the pile
• Droppings on the lid, rim or nearby ground
• Chewed holes in a plastic bin
• Scraps pulled out and scattered
• A nest of shredded material when you turn the pile

A closed bin is the best defense. Put a layer of quarter-inch hardware cloth under it so rodents can't dig up from below. NMSU Extension says mice can squeeze through a quarter-inch hole, so cover any vent holes with the same mesh. Metal or heavy plastic holds up better than thin plastic, which rodents chew.

• Closed bin with a tight lid
• Hardware cloth floor and vent covers
• Set on a level spot away from walls and woodpiles
• Well away from the house, garage and coop

Meat, fish, bones, dairy, oily food and cooked leftovers draw rodents. So does pet waste. Stick to fruit and vegetable scraps, coffee grounds, eggshells, leaves and yard trimmings. Bury fresh scraps in the middle of the pile rather than leaving them on top. Birdseed and spilled grain don't belong in compost either.

Turning the pile regularly disrupts nests and makes it less comfortable. A pile that heats up well also breaks down scraps faster, leaving less to eat. Keep it damp enough to compost but not soaked.

If you find a nest, treat it like any other. Rodent nests can carry hantavirus, so wet it down with disinfectant before you handle it. Wear gloves. See hantavirus-safe cleanup.

If rodents keep coming back, look at the rest of the yard. Chicken feed, fallen fruit, birdseed, pet food and woodpiles all add up. Rodents in chicken coops covers feed. For persistent problems, rat control and prevention and monitoring are the services to look at.

Inside city limits, the city's weed and litter ordinance and its trash rules require cart lids closed and yards kept clear. The property rules guide covers what the city requires.

Compost is rarely the only draw. Spilled seed under a bird feeder is easy food every day. Clean it up every few days, or switch to a feeder with a catch tray. Fruit trees drop fruit that rots on the ground through late summer and fall; pick it up. Vegetable gardens leave seed heads and stalks once they're done. Clearing those cuts the food supply right when mice are getting ready for winter.

Don't dig into it bare-handed. Wet the surface down, wear gloves and set snap traps in covered boxes around the base for a week or two. Once the catch stops, move the compost into a closed bin with a hardware cloth floor. Soak any nest you find with disinfectant before you handle it. If the activity is heavy or you see burrows under the pile, a provider can trap and look for where rodents are living nearby. See rat control.

If you see a rat-sized animal at the compost, check the tail. A furry tail with a white belly is a pack rat, the native woodrat. A bare, scaly tail is a Norway rat, which the state rodent guide says is sporadic in larger New Mexico cities and found in some farm areas. They call for different approaches, so it's worth a photo before you call. See rat control and pack rat control.

Mice are still the most likely visitors, and the same bin setup keeps all three out.

• Keeping Rodents Out of Chicken Coops and Feed
• Cleaning Up After Mice Without Breathing In Hantavirus
• Plague, Fleas and Pets Around Albuquerque
• City Rules on Yards, Weeds and Trash That Bear on Rodents

Services: Rat Control / Prevention and Monitoring / House Mouse Control

1. New Mexico Department of Health: Plague case in Bernalillo County (Sept. 2025)
2. New Mexico Department of Health: First hantavirus case of 2026 (March 2026)
3. New Mexico Department of Health: Domestic Rats and Mice
4. NMSU Extension Guide L-209: Rodent Control and Protection from Hantavirus