For decades, the standard answer to rats was a bait station full of poison. In California that's largely over. A series of state laws has banned most anticoagulant rodenticides, the blood-thinning poisons that made up most rat bait, for use around homes.
What changed, and when
- Second-generation anticoagulants (such as brodifacoum and bromadiolone) were restricted by AB 1788, which took effect in 2021, with only narrow exceptions.
- Diphacinone, a first-generation anticoagulant, has been banned for home use since January 1, 2024.
- Chlorophacinone and warfarin have been banned for most uses, homes included, since January 1, 2025 (AB 2552), with steep daily fines for violations.
The California Department of Pesticide Regulation publishes the details of each restriction.
Why the state did it
Anticoagulant poisons don't stay with the rat. A poisoned rat is easy prey, so the poison moves up the food chain to hawks, owls, bobcats and mountain lions. Pets can be poisoned the same way, or by eating the bait directly.
What's still allowed
Some non-anticoagulant baits remain legal, but the direction of the law is clear: poison is a last resort, not the plan. For homes, the standard approach is now:
- Inspect to find how rodents get in.
- Trap the ones already inside, with traps placed where they actually travel.
- Seal every entry point with metal mesh and sheet metal.
- Clean up droppings and nesting, and sanitize the area.
The upside of no poison
- No dead rat in the wall. A poisoned rat often dies somewhere you can't reach, and the smell can last for weeks. Trapped rats are removed.
- Pets and kids aren't near bait.
- It fixes the cause. Poison kills the rats inside but leaves the way in open. Sealing closes it.
More guides
This guide is general information, not a substitute for an on-site inspection. Sealwell is a referral service, not a contractor.
