Poison doesn’t close the gap.
Poison does a ton of harm. It spreads through insects, lizards, owls, hawks and pets, and the gap the mouse used is still wide open. The next mouse walks right in.
What we’ve seen around bait stations
We spend our days on rooflines and around foundations, and we see bait stations everywhere. Here’s what actually happens around them.
Insects carry it out
Roaches and ants walk in and out of bait stations and come out covered in the blue-green bait. We have photos and videos of hundreds of ants covered in blue, carrying it back out into the yard.
Lizards break the bags open
We’ve watched lizards tear bait bags open. Once the bag is broken, the bait isn’t contained anymore.
Owls eat the bugs, and the rodents
Burrowing owls eat big bugs, and sometimes rodents. A bug that’s been through a bait station, or a sick rodent, can become an owl’s next meal.
Sick rodents wander into the open
A poisoned rodent doesn’t drop on the spot. It gets sick and slow and wanders into the open, where owls, hawks and pets find it.
Predators rely on prey
On a bat exclusion job, we watched an American kestrel catch a bat right out of the air. Moments like that are a reminder of how much predators depend on prey.
Owls, hawks, kestrels and foxes hunt rodents and big insects every day. Put poison in the prey, and it ends up in the predator.
Fix the house, not the mouse. Seal the gap and nothing has to die.
How the harm spreads
The bait is built to be eaten
Rodent baits are flavored to attract animals, so pets and wildlife can take the bait too. Some baits are dyed blue or green so you can tell if a child or pet got into it.1
The animal doesn’t die right away
Most rodent poisons are anticoagulants. The animal bleeds internally and dies days later, still moving around in the meantime.2
It moves up the food chain
Hawks, owls, wild mammals, dogs and cats can be poisoned by eating poisoned prey. It’s called secondary poisoning.1 The strongest baits stay in animal tissue longer, which raises the risk to anything that eats them.2
Mice often die inside the house
Mice stay close to their nest, so poisoned mice often die inside the structure, in the walls where you can’t reach them.3
And the gap is still open
Nothing about the house changed. The next mouse finds the same opening, and the cycle starts again.
What works instead
Exclusion, sealing every opening, is described by the University of California’s IPM program as the most successful and permanent form of house mouse control.3
- Find every gap about the width of your finger. See the 8 entry points.
- Close each one with stainless steel or galvanized hardware cloth, or exterior-grade metal, sealed in with exterior-grade adhesives and sealants.
- If mice are already inside, use indoor snap traps along the walls while you seal, never instead of sealing.
- Keep food, pet food and birdseed in sealed containers.
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Mouse-proof my houseSources
- National Pesticide Information Center, Rodenticides Fact Sheet
- U.S. EPA, Restrictions on Rodenticide Products
- UC Statewide IPM Program, Pest Notes: House Mouse