[Tech Talk]

Eliminating that final rodent from an account can test the patience of the most talented PMP. Here’s how to ensure you’ll be successful the next time you encounter "Ratigan!"

Have you ever been in a situation where rodent control has come down to finally getting that last survivor? That’s the subject of this article: my observations on the last survivor and its successful elimination. We all have different names for these survivors and even our customers will give them colorful names, from time to time, such as "One-Eyed Jack." I prefer "Ratigan," the name of the main character from the 1986 animated movie, "The Great Mouse Detective."

Individual rats not only have managed to survive, but pest populations of rats are increasing all over the world. Rodent management science, however, is not keeping up with rat reproduction and evolution. We need to consistently improve our rodent management programs and adjust them as needed in order to be successful in eliminating "Ratigan."

A great rodent management program requires thorough inspections, meticulous observations on rat habitat and food activities, continuous learning, record keeping and trending, and additional information from the customer, whether commercial or residential. A great program should not be focused on the number of rats killed, but rather on the rats that survive to live another day. Rodent management programs are not successful unless they are diligent and constantly evolving.

There are several reasons why we might fail to capture or kill the last survivor, including one or more of the following:

• Not conducting a thorough inspection
• Not enough pre-baiting
• Not enough traps
• Too much food available and not enough sanitation
• Not using the food that "Ratigan" is eating or wants to eat
• Missing a few entry points in the rodent proofing plan

‘ROOF’ RATIGAN. Roof rats (Rattus rattus) are the most common rat species in southern California and in the southern United States. It’s been my experience that, because of the wide range of foods roof rats eat, we have to pay careful attention to what "Ratigan" is currently eating and then use this same food as the attractant in our traps. The key is to bait the traps without setting them. The traps should be left unset and baited for at least seven days. Rats are cautious feeders and it takes some time for "Ratigan" to become accustomed to the traps as a preferred source of food.

Successful rodent control is time-consuming and takes a lot of traps. Pre-baiting with a few different foods is a good idea to help determine preferred foods and baits. Checking traps daily also can provide information on where the rats are active and if more baited traps will be needed in an area. When you finally set the traps, you must be sure that you have more traps set than the number of rats present.

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The Elusive Roof Rat

The primary rodent our company deals with in California is the roof rat, but the range of this elusive rat species is wide — it’s found throughout the United States and all continents of the world.

Obviously, roof rats get their name because they tend to be found on roofs and other upper parts of buildings. But they can also be found under, in and around structures, and they only need a space of ½-inch to extrude themselves to get into buildings. Ranging in size from 6 to 8 inches long (not including their tails), their vision is very poor, and they are color blind. But they do have extremely strong senses of hearing, smell, touch and taste. They’re known for the damage they do by chewing on materials and eating stored foods. History tells us they were responsible for spreading bubonic plague in the Middle Ages.

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I once had a case where the elusive survivor had been running loose throughout a house for more than a month. It was not coming to any of the baited traps that had worked well for its relatives. Upon inquiry, we found that its preferred food was dark chocolate, the darker the better. All existing snap traps were unset, expensive dark chocolate was placed on the traps, and additional snap traps were added to the home in areas where the rat had been seen. After five days, and daily follow-ups to ensure that the bait was replenished where it had been consumed, the traps were all set to kill. The next day, we killed "Ratigan." We knew it was the last survivor because of subsequent thorough inspections and checking for any other feeding activity.

The goal of rodent control or of a successful rodent management plan is to eliminate the last survivor. To ensure that this happens, keep customers involved and be sure to review your findings with them daily. Communication will gain the customer’s confidence in your professionalism and help create the proper expectations. Finally, when "Ratigan" doesn’t come back again, everyone shares in your success.

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A member of Copesan’s Technical Committee, Fred Rozo is an Associate Certified Entomologist with Western Exterminator Co., Anaheim, Calif. He received his bachelor’s degree in political science from the University of California, Santa Barbara. Rozo helps develop and conduct training curriculum, performs quality assurance inspections, identifies specimens, handles pesticide concerns and heads up the company’s safety committee. He is a Board Associate Certified Entomologist in urban and industrial entomology and is a member of ESA, Pi Chi Omega and is a state director for PCOC.

Copesan is an alliance of pest management companies with locations throughout North America. To learn more, visit www.copesan.com.