A dead rat being cleared from a ceiling.
By Marcia Anderson
In recent years, there has been a dramatic shift in programs aimed at controlling rodents, especially in urban areas. Through the use of non-toxic biomonitoring baits, New York City rodent control specialists are improving their pest management techniques to become more effective at tracking rodents.
Biomonitoring baits are essentially non-toxic food blocks for mice and rats with additives that allow for tracking. The baits contain human food-grade ingredients, making them highly attractive to rodents in both taste and texture.
There are two types of biomonitoring baits – one that incorporates a biofluorescent marker and a second that incorporates a dark pink dye. After they are digested, the marker additives are excreted in the rodent scat (feces). Under black light, even the faintest of scat with the bio fluorescent marker glows brilliantly. In contrast, the pinkish scat from the other bait product is easily detected in normal light.
Biomonitoring baits can assist in controlling rodent infestations, especially in sensitive locations such as in schools, childcare centers, and medical facilities. In these locations where pesticides are not desired or allowed, an Integrated Pest Management (IPM) approach is critical. IPM is a smart, sensible and sustainable approach to managing pests that focuses on pest prevention and incorporates a diversity of control tactics, including pesticides.
Mouse in insulation of a home
In areas where other mammals or birds of prey frequent and rely on rodents as part of their diet, these sensible tracking baits have no impact on non-target animals. They help pest management professionals determine the paths rodents travel between their nests and food sources. By tracking the brightly colored or glowing droppings, a pest management professional can also determine the species of rodent, size of the infestation, range, entry locations, harborages and approximate nest locations.
Biomonitoring baits can be deployed in outdoor bait stations to determine if rodents are living in or entering a building. If entering the building, these baits can the direct pest management professionals to the openings that need to be sealed. When used in indoor stations, the baits show the paths rodents are using as well as their nest site(s).
Both types of monitoring baits are currently being used in New York City. Strategically placed, they can even detect on which floors rodents are harboring. They are a smart addition to any IPM program.
In addition to rodents, the fluorescent biomarker has also been used to detect cockroach movement, their locations of entry, and even their harborages. Are they entering from the basement, sewers, neighboring structures, pipes, or wall voids? The cockroach frass (feces), although much smaller than rodent scat, is still detectable with black light, and glows just as brilliantly, uncovering their travel and harborage secrets.
Biomonitoring effectively addresses the pest monitoring step in a successful IPM program. It allows for a focus on the underlying issues that make areas attractive to pests. The baits can also assist community sanitarians in controlling the NYC rodent population while protecting Fordham University’s hawks at the same time. Read a related 2012 blog that highlights the Disappearing Pigeons and Rats from a Bronx High School.
Technical information on rodent biomonitoring was provided to the author by Dr. Bobby Corrigan, RMC Pest Management Consulting. For practical implementation of biomarkers in NYC go to: www.pctonline.com/boimonitoring-rodents-Corrigan.aspx.
About the Author: Marcia is with EPA’s Center of Expertise for School IPM in Dallas, Texas. She holds a PhD in Environmental Management from Montclair State University along with degrees in Biology, Environmental Design, Landscape Architecture, and Instruction and Curriculum. Marcia was formerly with the EPA Region 2 Pesticides Program and has been a professor of Earth and Environmental Studies, Geology, and Oceanography at several universities.