QUESTION:
I recently had a problem with an evasive rat in one of my accounts. Several follow up visits and nothing but tripped traps!! My Technical Director accompanied me to the account and applied a rodent repellent to the burrow and the tops of the bait stations. I haven’t had any issues since. I would really like to try this on mice in my residential accounts and would like your thoughts on how to implement the procedure. I currently use mechanical devices on initial service coupled with exclusion, then finally install bait for continued control and monitoring. Your advice greatly appreciated.
ANSWER:
That is interesting that a repellent might actually have resolved a lingering issue, but we do have a number of good rodent repellents now, so perhaps this rogue rat really did exit the structure and your exclusion work now keeps it out. One repellent Univar sells is called Detour, with white pepper and garlic oil as the highly irritating active ingredients, and its manufacturer suggests using this in a wide variety of locations to cause rodents sufficient skin irritation that they move on. It is labeled for both indoor and outdoor use on “surfaces” where rodents are expected to travel, so fairly broad labeling allowing interpretation for where it can be used. Rodent burrows is one location, but applying it to the tops of the bait stations was interesting. This, of course, would probably make that station unacceptable to this rodent and any others that approach in the near future.
This repellent, and possibly others that rely on active ingredients that cause skin irritation, would of course also be irritating or painful to any humans who contacted it, so the Label does caution NEVER to use it where people could come into contact with it, and probably a good idea not to let the family dog lick the surface either. Another rodent repellent is Rat Out Gel, using the same ingredients but with perhaps an even more open Label, allowing use indoors and outdoors along “any” route rodents may travel. Some of these could be possible ways to provide some protection for vehicles, where rodents get up into the engine compartment and destroy wires and tubing. I don’t know what repellent you used in your case, but white pepper, garlic oil, and mineral oil seem to be consistent ingredients for the rat and mouse repellents where you can get actual contact with the traveling rodent.
Complete exclusion is the ultimate answer to rodent problems indoors, and these repellents are Labeled for use primarily to help drive the rodents out of the structure and then sealing the entry points permanently to prevent future indoor problems. In theory, if you can make life miserable enough for the rat or mouse indoors it may go outside to cool down and compose itself. Of course, if you are successful in eliminating all available food resources indoors, as the overall rodent management would call for, then the rodent is going to go outside to find food anyhow, and only return for harborage. I’m not certain what the need would be for repellents once you feel you have the rodents out of the home. Your trapping program along with exclusion could rid the structure of the pests anyhow, and then applying repellents outdoors might not offer any benefit. This is assuming you were able to locate all the entry points and seal them, rather than knowing of existing entry points, leaving them open, and applying repellent around them. You would not want to seal the rodents inside with repellent barriers they are forced to cross.
On the baiting issue, I am always torn about the use of rodent baits indoors. I suspect you are well aware of the potential problems indoor baiting can pose – dead rats where you cannot get to them for disposal, pets accidentally finding and eating the bait, stored food pests getting into the bait. If you feel the home is free and clear of rodents perhaps placing traps strategically along probably travel routes would be a better long term monitoring method. If your baiting is outdoors that is different, although baits are subject to spoiling and needing to be disposed of, so using them only as needed would be advisable. However, I understand the need to do something on the exterior to eliminate rats and mice that do come to the structure and begin to probe for entry points. By the way, a speaker once presented some research findings at a conference and addressed the belief that placing rodent baits in stations around the exterior of structures might somehow DRAW the rodents to the structure. Their research indicated that this does not happen.
View past Ask Mr. Pest Control questions.
Pest QuestionsJanuary 21, 2012
