The Least Wanted

By Sam Gazdziak, Senior Editor

Things that crawl, fly or go bump in the night can cause severe problems unless they’re eliminated.

With all the safety issues and concerns that come with operating a successful meat-processing plant, the last thing a processor wants to worry about is an infestation of the four-or-more-legged variety. Mice, flies, roaches or any other kind of pest can lower the sanitary conditions of a facility, pose a risk to employee and food safety and generally make for an unpleasant working environment.
When faced with any kind of pest, the recommended route is to hire a professional pest-control expert, says Dr. John Hopkins, assistant professor and extension entomologist at the University of Arkansas’ Department of Entomology.
“In a meat-packing or food-processing facility, it’s not really a do-it-yourself type of program,” he explains. An expert, he explains, will be fully versed in integrated pest management and can use chemical and non-chemical measures, as well as trapping when necessary.
“They will use a full spectrum of control tactics,” Hopkins notes.
Integrated pest management involves gathering the most information to make the best decisions in regards to pest control. Ideally, it would be implemented before there is an emergency need for pest control or when there is a risk of violating government regulations. But it takes into account such things as the long-term effects of using pesticides, not only to employee health but also to profitability and the possibility of pesticide resistance. Solutions that might be taken into account include introduction of natural enemies, cultural management, temperature and other physical controls, sanitation and pesticides.
To keep a plant’s critter count down, Hopkins advises to keep the plant in a proper state of repair, both inside and outside. That includes eliminating ways for vermin to get into the facility as well as removing places that would be harborage areas on the outside. Pallets or boxes stacked up on the outside of the building would make a nice home for rodents, as would large bushes next to the building.
“You want to keep the outside of the building clean, and keep shrubs trimmed back from the edges of the buildings,” he says.
What follows are a few of the pests that might terrorize meat- and poultry-processing plants, and how to deal with them.
Cockroaches of various species can contaminate food with their droppings, their bodies or the bacteria they carry. Several types of Salmonella and Staphylococcus can be traced to their presence, along with dysentery and cholera. They hide during the day and only come out to feed at night. They eat almost anything man eats, as well as glue, paste and fecal material, among other human inedibles.
The presence of cockroaches can usually be seen by cast skins, egg sacs and droppings. If there’s a high infestation, there may also be a noticeable musty smell. The use of insecticides and the destruction of their feeding and breeding grounds are needed to get rid of them. Professionals are often needed in the application of the pesticides because of government regulations that determine where and how the chemicals can be used in food-processing plants.
Outside of a home or office, flies help in the decomposition of animal carcasses and are a food source for many animals. Inside a building, they are annoying at best and a health and food hazard at worst. There are several different types of flies that might take up residence in a food-processing plant, including the house fly, the fruit fly and the green bottle and blue bottle fly. If they are to be found anywhere inside a building, it would most likely be near decaying organic matter, whether it’s in garbage bins or animal carcasses. They can carry diseases, making it critical that they be kept out of processing plants.
Keeping outdoor trash bins far from the facility is one way of keeping flies on the outside of a plant. Inside or outside, refuse bins and the areas around them should be cleaned and sanitized regularly. Windows should be screened, and wind curtains can be used to prevent them from flying indoors.
If a processing facility has readily available food, water and shelter, rats and mice may soon consider the building home. Without proper plant sanitation, there will be plenty of things in that plant on which rodents can feed. Dripping water pipes will provide a water source for rats, and piles of boxes and tall weeds can supply the shelter. Rodents can contaminate food products with both their own fecal material and with anything on their feet that they track into a plant — rats and mice are not known for traveling through clean places.
In the event of a rodent infestation, droppings will be visible and loose food items will indicate where they have been feeding. Rats tend to use the same pathways while moving between food, drink and shelter, and as they rub their bodies against a wall or other vertical surface as they travel, they will form a greasy mark against the surface.
Taking away the sources of food, drink and shelter will discourage the rats from entering a building. Plants can be designed to be rodent-proof, drainage ditches and other standing water sources should be eliminated, and food items should be kept in rodent-proof containers. Warehouses should be kept orderly, and a strip of light-colored paint should be should be painted on the floor around the walls of a warehouse to easily identify any signs of rats. NP
For more information: A training manual, Food Manufacturing, Processing and Storage Pest Control, is available from the Department of Entomology at the University or Arkansas at
Pest control around live animals
If a processing plant also has a slaughter area, measures have to be taken to control pests that might gather there. Removing manure and other organic manner on a regular basis is critical to prevent swarms of flies from surrounding the area. Standing water can attract mosquitoes, whose bites can irritate the animals as well as spread disease. There are some insecticides that are safe for use around livestock, but an expert should be consulted before any such measures are introduced.
Another concern with live animals is lice and other vermin that can cause discomfort to the animals and lead to a less-than-optimal carcass. Hogs, for example, are susceptible to hog lice and mites that cause mange. There are sprays, powders and feed additives that can treat these problems, but they need to be used on a regular schedule, both at the farm where the animals are raised and at the slaughter facility.
For more information about live animal pest control, visit Purdue University’s Department of Entomology home page at