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The five most common questions about rodents and rodent control

Each year we receive hundreds of calls seeking advice on how to control or prevent rodent issues in and around homes. Here are answers to the five most common questions to help you navigate your way to a rodent-free property.

The rats aren’t taking the bait on the snap traps. What am I doing wrong?

You may not be doing anything wrong! Rats are neophobic, meaning that they are fearful of new things in their environment. One trick is to bait the trap for several days without setting it. Replace the bait each day, allowing the rats to familiarize themselves with this food source. After a few days, bait and set the trap (arm the spring).

What kind of bait should I use on the snap traps?

Roof rats and Norway rats have similar food preferences, and there are lots of good bait choices. Peanut butter, bacon, chewy candy bars and moistened oatmeal are just a few examples.

Do the ultrasonic devices that you plug into the wall work to repel rats?

We wish that rodent prevention was as easy as plugging a device into a wall and walking away. Sadly, there is not enough data to suggest that these devices are an effective way to repel rats.

What type of trap works best, snap traps or electric traps?

Electronic traps and snaps traps are both effective for trapping rats and mice. Place them where the rodents are most active (e.g. near entry holes, along walls, in dark areas, behind appliances or where you see droppings).

Can I trap rats and relocate them?

No. In California it is illegal to trap and relocate animals. If you trap a live rat on your property, you must either euthanize it at once or release it on the site where it was trapped.

For more information about rodent control visit If you are experiencing an issue with rodents, contact the District for advice. You can schedule a free inspection at 707-285-2200 or online at

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