Keep Rats Out of Your Urban Chicken Coop
By Maureen Mackey, Oregon
Keeping chickens provides so many benefits, it’s no wonder many city-dwellers have in-stalled coops in their backyards. There is no need to live on a farm to enjoy having fresh, wholesome eggs to eat, improved soil quality and natural pest control.
But there’s a snake in this urban Garden of Eden, and in this case it’s a furry, four-legged rodent. Like uninvited houseguests that won’t leave, rats may help themselves to your poultry hospitality if you don’t take steps to stop them. And rats pose a definite threat to chickens and their owners.
Portland, Oregon, is just one of many cities across the country that has embraced the popular trend of backyard chicken coops. And Portland has a rat problem, which makes people wonder whether chicken coops are making the problem worse.
Christopher Roberts, Public Health Vector Specialist for Multnomah County Vector Control in Portland, has seen a rise in complaints on his job. His office gets about 1,000 rat-related complaints a year.
“The complaints we hear most often is that, ‘My neighbor has chickens and now we have rats.’”
Roberts is quick to point out that backyard chickens don’t create a rat problem; they just provide rats that are already in the area with another opportunity for food.
“Rats don’t appear out of nowhere. In any city the older parts are more prone to rats. They can live in well-established vegetation or they can be in the sewer.”
Doug Bridge, owner of Portland Homestead Supply Company in Portland, Oregon, would agree. He keeps a flock of chickens both in his Southeast Portland home backyard and at his store.
“In any urban setting rats are a fact of life, so the question, ‘Do chickens attract rats?’ is somewhat misleading.” He believes, the construction work on the sewers in Portland is causing a bigger rat problem than chicken coops.
Roberts has also identified a culprit for Portland’s rat woes, and it’s not chickens.
“The number one source of any rat problem is hanging bird feeders.” The next major source, he added, is backyard compost. Along with those two sources, rats are attracted to pet food, including food left out for dogs and cats, and feed for chickens or goats.
“Any source of food runs the risk of attracting rats,” Roberts added. “They need a consistent food source to establish themselves.”
Another urban haven for backyard chicken enthusiasts is Berkeley, California. Derek DiMaggio, Berkeley vector control technician, agrees with Roberts that any food source will draw rats, including pet food and birdseed.
“Birds are messy eaters — they spill their seed on the ground, and this creates an accumulated buffet. If rats become used to this food source it can become an on-going problem.”
DiMaggio says he’s seen rats that have easy access to a food source become acclimatized to their surroundings and as a result very relaxed — almost like domesticated pets. And chicken coops can pro-vide a very convenient food source for rodents.
“A chicken coop can be a big problem depending on how it’s kept,” said DiMaggio. “If it’s not properly constructed and rodent-proof, it can actually cause rodent activity during the day.” Seeing rats during the day is unusual, he added, since these wary creatures are usually active only at night.
Typically, rodent invaders are either roof rats, or more commonly, their larger and more aggressive cousin the Norway rat. These rodents can enter a structure through a hole no bigger than a quarter. Norway rats, in particular, are likely to be present if there is a problem with the sewers, especially broken pipes, which is common in the sewer systems of older cities.
Evidence of a rat presence in your home includes scraping sounds in your walls, scratches and/or greasy rub marks (from a rat’s oily fur) on wood or painted surfaces, and burrows in the ground next to your coop or near a home’s foundation. Rats will often dig both an entry and exit hole and their holes are round and smooth. A burrow or hole adjacent to a sidewalk or in a front lawn or parking strip usually indicates a Norway rat that’s dug up to the surface from a cracked sewer line.
Chicken owners will know pretty quickly if they have a rodent problem if they observe rat droppings in their coops, particularly near the feeders. Worst-case scenario, they may see their birds attacked or eggs eaten.
While the idea of rats attacking chickens is upsetting, rodents aren’t the predators that city chicken owners like Bridge worry most about.
“Dogs have been our number one predator by far, and we have lost chickens to hawks, raccoons, and a possum,” Bridge said. ”In our decade of having chickens at home and at our store, we’ve never had an issue with rats disturbing our chickens.”
Bridge’s chief method of dealing with any predator is a simple one. “We lock our chickens in every night. This is the most important predation control we do. We do let our chickens range in the yard and around our business during the daylight hours.”
But predation isn’t the only headache rats can create for urban chicken owners. Public health and safety are other concerns. Rats can cause expensive structural damage and contaminate food and areas where food is grown or prepared.
Rats who are filching food from your chickens could translate to rats seeking shelter in your home and that’s very bad news. Rodents have been known to cause house fires by gnawing on electrical wires and plugs, not to mention in-house flooding by biting through the flexible water pipes that connect to dishwashers and sinks.
Rats rarely go beyond 300 feet of their burrows or nests, making it convenient for them to take shelter in one place, such as a home’s basement or crawlspace, and get food somewhere else — like you or your neighbor’s adjacent chicken coop.
According to the University of California Statewide Integrated Pest Management findings, Norway rats can cover a circular area of about 100 to 150 feet in diameter when they are on the prowl for food and water.
As Roberts put it, “Rats don’t care about property lines.”
Rats can also carry serious diseases, including salmonella, leptospirosis and murine typhus. And then there’s that bane of the Middle Ages, the plague. Though the incidence is rare, humans can still contract this disease via the bite of a rat flea. The possibility of an outbreak exists if the rat population increases, warns Berkeley’s Environmental Health Division on its website.
The University of California’s research shows that just one well-fed female Norway rat can produce about four to six litters a year. Plus, she can wean 20 or more of those offspring every year, too. Multiply those numbers by the females in a large colony of rats and you can see the potential for explosive population growth.
So, what’s the best way to keep big city rats away from your city chickens?
“In my experience, it all depends on your coop design,” said Bridge. A lot of chicken coops are made to keep chickens in, not rats and other predators out.
Roberts recommends enclosing your entire coop with ¼-inch steel hardware cloth, and sinking or burying that cloth into the ground one foot deep and another foot extending out from the structure. He cautioned against using traditional chicken wire, because mice and small rats can fit through it and larger rats can dig under it.
Bridge learned this lesson through hard experience.
“My first coop was on the ground, and I lined the bottom with chicken wire rather than hardware wire. Within a year, the rats had successfully tunneled through the flimsy chicken wire. I built my last coop two feet off the ground to make cleaning far easier via a drop floor, and have seen no evidence of rats in or around this coop.”
Another important step in keeping rats away from your flock is cleaning up after feedings and controlling seed spill-age. Putting birds on a feeding schedule helps, too.
Cities like Portland and Berkeley offer free rodent inspections and advice to coop owners. Part of DiMaggio’s job is to talk to backyard chicken owners about rodent harborage and the attendant health hazards, and to inform them about city statutes.
To avoid paying a fine or being required to relocate your coop or remove it altogether, it pays to research city code regulations and enforcement. For example, city laws may require a coop to be built anywhere from 15 to 40 feet or even farther from a neighboring structure. Codes also address the number and type of birds allowed.
Once you’re in compliance with your local municipal codes, here are a few additional tips to deal with a rat problem or prevent one from developing:
• Design a coop that rats can’t enter or tunnel under — or better yet, if possible, build one that’s free standing.
• Store all food in gnaw-proof containers.
• Discontinue open feeding and put your birds on a feeding schedule. And if you do notice evidence of rats, put chicken feeders away every night.
These steps should help keep your coop rat-free and make sure you and your birds stay healthy and happy.
Maureen Mackey writes from Beaverton, Oregon.