Why chicken coops attract Norway rats specifically
Norway rats follow three attractants: food, water, shelter. A chicken coop provides all three in concentrated form. Spilled grain from feed dispensers provides a consistent, high-calorie food source. Water dispensers for the chickens provide water. The coop structure provides warm, sheltered nesting space near the food source. This is essentially a Norway rat resort. The rat population that establishes around a coop is not an incidental visitor — it's a stable colony with year-round habitat. Metro Vancouver's mild winters mean there's no seasonal break in this dynamic.
The City of Vancouver's bylaw on urban farming requires that chicken keeping not create a pest attraction issue. A rat-infested coop can trigger a bylaw complaint from neighbours and a requirement to remediate or remove the chickens. Several Vancouver urban farmers have faced this exactly. The solution is not to give up the chickens — it's to manage the coop in a way that doesn't establish a rat colony.
The hardware-cloth apron: the single most important intervention
Norway rats burrow. A standard chicken run with chicken wire sides and no floor provides no barrier to a rat that simply digs under the perimeter. The hardware-cloth apron addresses this: 19-gauge galvanised hardware cloth buried 30-45 cm into the ground around the full run perimeter, then bent outward horizontally for another 30 cm at the base (the L-shape). When a rat tries to burrow under the apron perimeter, it hits the horizontal section and gives up rather than navigating the bend. This is more reliable than burying wire vertically — vertical wire eventually lifts as soil shifts, where the horizontal L-shape resists lifting.
Feed management: the other half of exclusion
Hardware cloth stops burrowing access but doesn't eliminate the attractant. Feed management works in parallel: use covered feeders that close when chickens are not actively eating, rather than open trays that leave grain accessible overnight. Remove feed from the coop at dusk — rats are nocturnal and most coop feeding happens at night when chickens don't eat. Store feed in rat-proof metal containers with secure lids, not in the original paper sacking (Norway rats chew through paper in minutes). Water dispensers can stay, but elevated nipple drinkers that don't spill on the floor reduce the standing-water attractant.
- Install hardware-cloth apron around the full run perimeter — 19-gauge, quarter-inch mesh, 30-45 cm deep with 30 cm horizontal L at the base.
- Elevate the coop floor at least 30 cm off the ground so the underside is accessible for inspection and doesn't create a protected nesting space.
- Switch to covered feeders and remove feed overnight.
- Store all grain feed in metal containers with locking lids.
- Place tamper-resistant bait stations (first-gen anticoagulant, post-SGAR) against the outside of the apron perimeter, at least 1 m from the run.
- Inspect the apron perimeter monthly for burrowing attempts — look for fresh soil disturbance at the apron edge.
- Clear brush and ground cover within 1 m of the run to eliminate concealed approach routes.
Are chickens at risk from rats?
Healthy adult chickens are not typically at risk from Norway rats — rats that are outweighed by a factor of 5:1 generally don't attack them. Chicks and bantam breeds are a different matter: very small chickens can be vulnerable to rat attack at night. Roosting chickens (locked inside the coop after dusk) are safe from ground-level rat access if the coop itself is properly constructed and hardware-clothed. The primary risk from rats in a coop is not direct attack — it's disease transmission through feed and water contamination with rat urine (leptospirosis risk to people handling eggs and cleaning the coop, Salmonella risk from contaminated feed consumed by chickens and potentially passed to eggs).