Rats in your compost bin: a Metro Vancouver gardener's playbook

What makes a compost bin attractive to rats

• Food residues at ambient temperature (no compost heat): rats can dig and eat directly from the bin contents.
• Loose-fitting lid or open top: direct climbing access.
• Soil-floor or unsealed base: rats burrow up through the bottom.
• Animal products (meat, dairy, oily food, cooked grains): high-energy food that rats specifically target.
• Static contents (rarely turned): cool centre temperatures, easy to nest in.
• Adjacent cover (ivy, woodpile, dense shrub): runway from cover to bin without exposure.

The rat-proofing checklist

1. Install a 19-gauge galvanized hardware cloth panel under the bin (quarter-inch mesh). Extend at least 30 cm beyond the bin perimeter, anchored with garden staples.
2. Replace any worn lid with a heavier lid or weight the existing one with a brick. The lid must close fully, with no gap.
3. Remove animal products entirely — meat, dairy, oily food, fish. Even one banana peel coated in fish oil is a draw.
4. Cooked grains and bread can also draw rats; many compost guides recommend skipping these too.
5. Turn the bin weekly. Active composting reaches centre temperatures of 50-65°C, which both processes the material faster and makes it inhospitable to nesting.
6. Clear the 1 m perimeter of dense vegetation and woodpiles. Rats need cover to approach the bin; eliminating cover reduces approach attempts.
7. Inspect monthly for signs — droppings on the lid or beside the bin, gnaw marks on plastic, runway smudges along the back panel.

Vancouver's rodent-proof composting bylaw context

Vancouver's Solid Waste Bylaw and associated Metro Vancouver Integrated Pest Management guidelines require property owners to maintain composting systems in a way that does not attract pests. This isn't enforcement-heavy in practice, but it does mean that if a property owner maintains a visibly rat-infested compost bin that is contributing to pest pressure on adjacent properties, a complaint to the City's Environmental Health office can trigger an inspection and a notice to fix. Most neighbourhoods with rat problems in East Van and Mount Pleasant have several such sources per block; the complaint process addresses individual properties, not the systemic gap.

When compost management isn't enough: the structure connection

Here's the pattern we see repeatedly: a homeowner properly rat-proofs their compost bin, eliminates the outdoor food source, and then starts hearing rats inside the house. They blame themselves. In reality, the compost was sustaining a rat population that was exploring the property's structural gaps. When the food source was eliminated, the pressure to enter the structure increased because the rats had already found the entry points during their foraging runs. Eliminating the outdoor food source is the right first step — but if you have an established yard population, structural exclusion has to follow. Starving rats out without sealing the structure just drives them inside faster.