Awaiting expert review. This page covers safety or regulatory rules that change over time. It is kept out of search results until a qualified reviewer has checked it; the sources below are dated so you can verify each point.
Quick answer
A rodenticide is a pesticide made to kill rodents such as mice and rats, almost always mixed into a food bait, and most kinds work by stopping blood from clotting.
Because rodent baits are food, children, pets and wildlife can eat them too, so federal and state rules limit who can buy them, in what form and where they may be placed.
Quick facts
The key facts about Rodenticide, with sources:
- Active ingredients reviewed by EPA
- 11, in three groups 2
- First-generation anticoagulants
- Warfarin, chlorophacinone, diphacinone 2
- Second-generation anticoagulants
- Brodifacoum, bromadiolone, difenacoum, difethialone 2
- Non-anticoagulants
- Bromethalin, cholecalciferol, strychnine, zinc phosphide 2
- Anticoagulant time to death
- Typically 4 days to 2 weeks after feeding starts 1
- California
- Most anticoagulant uses prohibited since Jan 1, 2025 (AB 2552) 3
Key takeaways
- Most rodenticides are anticoagulants that cause death by bleeding several days after the rodent eats them.
- Second-generation anticoagulants are the most hazardous to wildlife and are not sold for consumer use.
- Owls, hawks, foxes, cats and dogs can be poisoned by eating a poisoned rodent, not just the bait.
- Consumer products must come in bait stations with block or paste bait; loose pellets are no longer allowed.
- Traps and sealing entry points are the first steps; extension experts call snap traps the safest way to remove rats.
Rodenticides explained simply
A rodenticide is rat or mouse poison, mixed into a food bait so rodents eat it. The EPA notes rodenticides are used in homes, farms and other places against pests from house mice and rats to voles, gophers and ground squirrels 2.
Most are anticoagulants, which stop blood from clotting so the rodent dies from bleeding, typically between four days and two weeks after it starts feeding 1. The delay is deliberate: rats avoid new foods, and a slow poison keeps them from linking sickness to the bait 4.
Non-anticoagulants work in other ways. Bromethalin attacks the nervous system, cholecalciferol is vitamin D3 that turns toxic in very large amounts, and zinc phosphide releases a toxic gas in the stomach 2.
Every rodenticide is a registered pesticide, so its label sets who may use it and where 5.
First vs second generation
First-generation anticoagulants usually need several days of feeding. Second-generation ones were made from the 1970s on to kill rodents resistant to the first group and can kill after one night’s feeding. They also stay in animal tissues longer, which is why they carry more risk to wildlife 1.
How an anticoagulant bait works, step by step
- Bait is found. A rat or mouse finds a bait block in a station along its path. Rats may avoid a new station for days or weeks 4.
- Feeding. The rodent eats. First-generation products need repeated meals; second-generation can be lethal in one 1.
- Clotting stops. The poison blocks the body’s clotting, and internal bleeding starts 2.
- Delay. Death typically comes 4 days to 2 weeks after feeding begins, and the rodent may keep eating bait in that time 1.
- Carcass risk. A rodent that fed several times can carry many times the lethal dose, so predators or scavengers that eat it can be poisoned 2.
- Rodent eats baitOften more than once
- Clotting failsInternal bleeding begins
- Days passTypically 4 days to 2 weeks
- Rodent weakensEasier prey, still carrying poison
- Predator or pet eats itSecondary poisoning
This chain is the main reason EPA and California rules limit second-generation products. Source: [1] [2]
Rodenticide types and how they work
| Group | Active ingredients | How it works |
|---|---|---|
| First-generation anticoagulants | Warfarin, chlorophacinone, diphacinone 2 | Block clotting; most toxic with several days of feeding 1 |
| Second-generation anticoagulants | Brodifacoum, bromadiolone, difenacoum, difethialone 2 | Block clotting; often lethal after one feeding; persist in tissues 1 |
| Bromethalin | Bromethalin 2 | Nerve toxicant causing breathing distress 2 |
| Cholecalciferol | Vitamin D3 2 | Toxic in massive doses, especially to rodents 2 |
| Zinc phosphide | Zinc phosphide 2 | Releases toxic phosphine gas in the stomach 2; acts within hours 4 |
| Strychnine | Strychnine 2 | Nerve toxin causing convulsions 2 |
UC IPM notes new evidence that secondary poisoning can also happen with bromethalin, so non-anticoagulants are not risk-free for wildlife 4.
Example: how package size sorts who may buy what
The EPA uses package size to keep the riskiest products away from consumers. These are the published minimums and maximums, not amounts to use.
| Product type | EPA package rule | Who it is for |
|---|---|---|
| Consumer bait station product | One pound of bait or less; ready-to-use station 21 | Homeowners |
| Professional, first-generation or non-anticoagulant | At least 4 pounds per container 1 | Structural pest control pros |
| Agricultural, second-generation | At least 8 pounds per container 1 | Use in and near farm buildings |
| Professional, second-generation | At least 16 pounds per container 1 | Structural pest control pros |
Large containers are not to be sold in grocery, drug, hardware or club stores 1. If you see a big tub of loose pellets for sale to the public, something is wrong.
Where you will see rodenticide on paperwork
On a service ticket, a technician should list the product name, EPA registration number, active ingredient and where each bait station sits. A station map is a sign of good practice.
On a rodent control quote, look for “exterior bait stations,” “interior trapping,” “exclusion” and the number of service visits. Ask which active ingredient will be used and why. Our guide to what pest control contracts should say covers these terms.
On a product label, you will find the signal word, the active ingredient, where stations may go (indoors, or indoors and outdoors within 50 feet of buildings) and first-aid steps 1.
At a vet or doctor, the active ingredient decides the treatment, so keep the package.
Where rodenticides help
- Rodents damage property and food and can spread disease; the EPA notes rodenticides help protect public health 2.
- Baits can reduce large outdoor populations faster than trapping alone.
- Delayed action works around rats’ wariness of new foods 4.
- Tamper-resistant stations keep bait away from children and pets when used as the label says 1.
Drawbacks and limits
- All rodenticides are toxic to non-target animals, pets and people 4.
- Secondary poisoning harms predators and scavengers that eat poisoned rodents 2.
- Rodents may die inside walls, where no one can reach them.
- Rats can avoid stations for days or weeks, and roof rats may not enter stations at all, recent research shows 4.
- Baits do nothing about the gaps that let rodents in; without sealing, new ones arrive.
What drives the cost of a baiting program
Station count and visit frequency matter most to a baiting quote. Baiting is not priced here; a fair figure would take many dated local quotes.
A home perimeter needs stations spaced along travel routes, checked on each visit. Interior trapping, carcass removal and exclusion (sealing gaps) add labor. In California, anticoagulants are largely off the table for homes, which shifts plans toward traps, exclusion and non-anticoagulant products 34.
Stations and bait carry no warranty, though the service may, so ask whether exclusion work carries a guarantee. Our rodent exclusion tool lists the openings to seal, and the cost guide explains quotes.
How a professional rodent plan uses rodenticide
- Identify the rodent. Mice, Norway rats and roof rats need different placements 4.
- Seal entry points. Exclusion keeps new rodents out; see rodent exclusion.
- Trap indoors. Snap traps remove rodents inside without leaving them to die in walls 4.
- Bait outdoors if justified. Tamper-resistant stations go on travel routes, secured so they cannot fall where children or pets find them 41.
- Check and remove carcasses. Collect dead rodents found after baiting 4.
- End the program. Remove and dispose of uneaten bait when control is reached 4.
If a child or pet eats rodent bait
Act at once, even with no symptoms, because anticoagulant signs can take days, and keep the package. For a person, call Poison Help at 1-800-222-1222 (free, confidential) 6; call 911 for bleeding, seizures or collapse. For a pet, call your veterinarian or an emergency animal clinic right away.
Applicators must be licensed by the state, and some rodenticides are restricted use 4. See pest control licensing and the rodent control service page.
Living with bait stations
- Keep stations locked and fastened in place, so they cannot be opened or carried off 14.
- Never add loose bait or move bait out of a station.
- Wear disposable gloves to handle dead rodents; bag them and put them in the trash 4.
- Take old anticoagulant products to a household hazardous waste site, as UC IPM advises in California 4.
- Keep sealing gaps and removing food and shelter so stations can come out sooner.
Check for rats on a schedule
UC IPM says control takes less time and less bait when numbers are low, so check for droppings and gnaw marks regularly 4. See our pest risk checklist.
Warning signs and when to call a professional
- Droppings, gnaw marks, smudge marks or burrows near the house 4.
- Bait stations that are damaged, open or out of place.
- A dead owl, hawk, fox or pet near an area where baits were used.
- A strong odor from inside a wall days after baiting.
- Rodents still active after weeks of baiting; call a licensed company to rethink the plan.
Federal and state rules
EPA 2008 risk mitigation decision. The EPA’s 2008 decision for 10 rodenticides set package limits and barred second-generation anticoagulants from consumer products 2.
Consumer products must be ready-to-use stations with block or paste bait; pelleted baits are no longer allowed in them 1.
Professional products must be placed in tamper-resistant stations wherever children under six, pets or nontarget wildlife have access, and for all outdoor above-ground use 1.
EPA registration review. In November 2022 the EPA issued proposed interim decisions for 11 rodenticides. They propose, among other things, making all second-generation anticoagulants, strychnine and zinc phosphide restricted use pesticides 2.
As of our check on 2026-10-11, the EPA page (last updated November 2025) still described these as proposals and named an interim decision as the next step, so check the EPA docket for current status.
California, AB 2552 (Chapter 571, Statutes of 2024). Effective January 1, 2025, Food and Agricultural Code section 12978.7 prohibits most uses of first- and second-generation anticoagulants in California, including residential and most commercial uses, with exemptions such as vector control agencies, some agricultural sites and declared public health needs 3.
Labels carry federal force under FIFRA and 40 CFR Part 156 5. See our pesticide safety guide.
Rodenticide vs other rodent control methods
| Method | How it works | Main advantage | Main risk |
|---|---|---|---|
| Rodenticide bait | Rodent eats poison 1 | Reaches many rodents | Pets, kids, wildlife; dead rodents in walls |
| Snap trap | Kills on contact | UC IPM calls it the safest, most effective, most economical way to trap rats 4 | Must be placed away from kids and pets |
| Glue board | Holds the rodent | No poison | Not recommended for non-professionals; never outdoors 4 |
| Exclusion | Seal entry points | Stops new arrivals | Needs skill to find every gap |
See glue boards for why they are a professional tool.
Rodenticide myths
- Myth Rodents die right after eating the bait.
- Reality Anticoagulant deaths typically come 4 days to 2 weeks after feeding begins, and rodents can keep feeding meanwhile 12.
- Myth Only the bait is dangerous to pets.
- Reality Pets and wildlife can be poisoned by eating poisoned rodents 2.
- Myth Non-anticoagulant baits are wildlife-safe.
- Reality UC IPM notes new evidence of secondary poisoning from bromethalin 4.
- Myth Stronger poison means faster control.
- Reality Rats avoid new objects for days or weeks, so placement and patience matter more 4.
- Myth Any rodent bait can be used in any state.
- Reality California prohibits most anticoagulant uses since January 1, 2025 3.
California’s rules are the strictest we found
California is the clearest example of a state going beyond the EPA. Under AB 2552 (Chapter 571, Statutes of 2024), effective January 1, 2025, most uses of anticoagulant rodenticides are prohibited, including home use and use around restaurants, grocery stores, schools, offices and parks.
Allowed uses include mosquito and vector control agencies, invasive rodent control to protect endangered species, declared public health emergencies, state-funded research and many agricultural production sites outside wildlife habitat. AB 2552 also added a daily civil penalty, under Food and Agricultural Code section 12997.8, for violations 3.
UC IPM adds that bromethalin, cholecalciferol and zinc phosphide are the rodenticides registered for rats and house mice in the state 4. Other states follow the federal rules unless they add their own.
When it matters to you, and what to do next
Start with sealing and traps. For a few mice or rats inside, snap traps and closing gaps usually solve it without poison 4. Consider baiting outdoors only when numbers are high, no children or pets can reach stations, and it is legal where you live.
If a company proposes rodenticide, ask which active ingredient, whether it is first- or second-generation, where each station goes, how carcasses are handled and when baiting will stop. Our guide to choosing a pest control company lists more questions.
Quick decision guide
For a few rodents indoors, seal and trap. Heavy outdoor activity calls for a licensed pro with tamper-resistant stations and exclusion. With kids, pets or wildlife nearby, skip bait or use the strictest placement, and in California anticoagulants are largely off limits for homes.
Questions about Rodenticide
How does rat poison work?
Most rat poisons are anticoagulants that stop blood from clotting, so the rodent dies from internal bleeding. Death typically comes 4 days to 2 weeks after it starts feeding, the EPA says. Other rodenticides work differently: bromethalin attacks nerves, cholecalciferol is toxic vitamin D3, and zinc phosphide releases a toxic gas in the stomach.
What is the difference between first- and second-generation rodenticides?
First-generation anticoagulants, such as warfarin, chlorophacinone and diphacinone, usually need several days of feeding.
Second-generation ones, such as brodifacoum and bromadiolone, were developed to kill rodents resistant to the first group and can kill after one feeding.
They stay in tissues longer, so they pose more risk to wildlife and are not sold for consumer use.
Can my dog or cat be poisoned by eating a poisoned mouse?
Yes, because the EPA explains that rodents can feed on bait several times before they die, so their bodies can hold many times the lethal dose.
Predators, scavengers and pets that eat them can be poisoned. This secondary poisoning is a key reason for tighter rules on second-generation anticoagulants. Call a vet at once if you suspect it.
What should I do if my child eats rat poison?
Call Poison Help at 1-800-222-1222 right away, even if your child seems fine, and have the package ready. Anticoagulant symptoms such as bleeding can take days to appear. Call 911 if your child is bleeding, having a seizure or is hard to wake. Do not wait for symptoms before getting advice.
Can I buy strong rat poison at the store?
Not the strongest kinds, because EPA rules limit consumer products to ready-to-use bait stations with block or paste bait, no more than one pound, and bar second-generation anticoagulants from consumer products. Professional products come in containers of 4 to 16 pounds or more and may not be sold in grocery, drug or hardware stores.
Is rat poison banned in California?
Most anticoagulant rat poisons are. Under AB 2552, effective January 1, 2025, California prohibits most uses of first- and second-generation anticoagulants, including home use.
Exceptions include vector control agencies, many farm sites, declared public health needs and protecting endangered species. UC IPM lists bromethalin, cholecalciferol and zinc phosphide as rodenticides registered for rats in the state.
Are traps better than rodenticide?
For most homes, yes: UC IPM calls snap traps the safest, most effective and most economical way to trap rats.
Traps remove rodents without leaving them to die in walls and without risking pets and wildlife. Pair traps with sealing entry points.
Baiting may help with heavy outdoor populations when stations can be placed safely and legally.
Why are rats not eating the bait?
Rats are wary of new objects and foods, so they may avoid a new bait station for several days or even weeks, UC IPM says. Roof rats may not enter stations even on their usual routes. Placement matters: stations should sit on travel paths, near burrows for Norway rats and up high for roof rats.
How should I get rid of old rat poison?
Follow the disposal directions on the label and your local rules. UC IPM advises Californians with old anticoagulant products to take them to a household hazardous waste facility. Never pour bait out, burn it or leave it where animals can reach it. Keep it in the original package until disposal so it stays labeled.
Sources
- U.S. EPA, Restrictions on Rodenticide Products, retrieved .
- U.S. EPA, Rodent Control Pesticide Safety Review, retrieved .
- California Department of Pesticide Regulation, Chlorophacinone and Warfarin: Restricted Material Status, Prohibitions, Allowed Uses (AB 2552, Chapter 571, Statutes of 2024), retrieved .
- UC Statewide IPM Program, Pest Notes: Rats (Publication 74106), retrieved .
- U.S. EPA, Introduction to Pesticide Labels, retrieved .
- National Capital Poison Center, About Poison Control (1-800-222-1222), retrieved .
Expert review
Written by the HyrePest Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Ingredient groups, modes of action, package rules, the 2008 decision and the November 2022 proposed interim decisions are from two EPA rodenticide pages checked on 2026-10-11.
California prohibitions and exemptions are from the CDPR letter on AB 2552. Trapping, placement and bait-shyness facts follow UC IPM Pest Notes 74106. Held (G-REV) until a vertebrate pest specialist or certified applicator signs off.
Suggest a correction. We fix errors and say what changed.