top of page
  • Writer's pictureChelle Hartzer

The Rats are Coming! (AKA: Shut the front door!)

The other day, I was doing a talk on rodenticides. Rodenticides are a hot topic right now, primarily because California has banned the use of second generation, anticoagulant rodenticides. Other states may try to do the same. The given reason for this ban is to protect wildlife. I’m not going to comment on whether or not this is shortsighted and may come back to bite (literally) CA. I'm also not going to cover the wildlife issue in this post, visit the amazing Dr. Niamh Quinn’s page for more on that. What I do want to talk about is what to do next, whether you are in California or just have concerns with rodenticides.

First, don’t panic. There are still some rodenticides available and if used correctly as part of an overall management plan, they can still be effective. There are a couple of problems to consider. With a decreased use of rodenticides, there will be more rodents and other control methods will have to be increased. More traps will have to be used and traps have to be checked more often. If your service frequency is monthly, when a rat hits a trap on the day after your service, that trap is ineffective for the next month. A trap is only effective if it is set. If there is a dead rat in it for a week, that’s a week that no other rodents can be caught in that trap. Imagine if you have heavy rodent numbers and have 20 traps set. On day one, all twenty traps catch a rodent. You know have the rest of the month that you have absolutely no traps working so the rodents can happily run around, feed, and breed. Trap placement becomes more important as well. While the bait stations were likely set as a perimeter to monitor for activity, traps have to be placed carefully to intercept rodents. Trap placement has to take into account where the rodents are running, where they are feeding, and where they are nesting.

Next, with the increase in rodent numbers, it becomes even more critical to seal structures and keep up with sanitation. Rodents need food and we provide that for them. An increase in rodent population (from lack of baiting) means rodents are looking for more food sources. They will be coming closer to structures, to dumpsters, to garbage bins and from there, getting into structures. Rodents will gnaw into plastic bags to get to trash. They will chew holes in structures to gain entry to the food sources inside. Because of this, more frequent inspections are needed to check for potential rodent entry points. It means replacing door, dock, and other seals more often which can be costly.


Lastly, be prepared for an increase in rodent borne diseases. Rodents carry many diseases and they carry ectoparasites that transmit many diseases. The plague still exists in the US and is present around parts of California in the wildlife. Typhus is spread by rats as well and California has experienced typhus outbreaks in the past. People often think of rodents as generally gross (they are) and there is a food contamination issue (there is). They often forget the myriad diseases that rodents can carry and spread. As rodents come in closer contact with people, there is more risk of disease.

This is a good reminder for everyone outside of California that rodent control is incredibly important. It also has to be done correctly and with thought. Not just throwing out a few bait stations or dumping a couple of traps by doors. IPM is about using multiple tools and using them as effectively as possible. Consider your current rodent control program. When was the last time trending data on captures and bait feeding was analyzed? Are the traps and stations still in the same places they were years ago when the account was set up? What’s the plan for when a rodent does get in? Maybe it’s time to review. Just because you can still use rodenticides doesn’t mean you can ignore traps, sanitation, exclusion, and how to use devices for best efficacy. For help with this, or any of your pest issues, contact us here!

18 views0 comments
bottom of page