Does your commercial property have rodents?

Oct 7, 2022, 11:14 AM by Fred Speer

The presence of rodents in a commercial facility – particularly one involved in food processing, storage, or retailing – can have far-reaching, negative financial and operational impacts. They also can put consumers who purchase the contaminated products that are produced, stored, transported, or sold at those facilities at risk.

To design, implement, and maintain an effective rodent management program in a food plant, both the pest professional and facility staff must be on the same page and know what to look for.

Dr. Bobby Corrigan of RMC Pest Management Consulting, who is one of the world’s leading rodent experts, says that an effective rodent program starts with good observations and a lot of investigation.

Noting the physical signs of a rodent infestation and factoring in the facility environment (e.g., age, construction method, location, surrounding environment, et al.) are the first steps to identifying a solution.

Rodent threats

What rodents threaten California commercial properties?

Mice, weighing roughly one ounce, and three to four inches in length, don’t necessarily look threatening. But don’t underestimate the negative impact these unwanted critters can have on commercial properties. The warm, dry conditions California has endured all summer has forced pests, including rodents, seek alternate water and food sources inside commercial structures. While mice do not require as much water as their rat cousins, they still have the need to feed, and your business is a prime target.

Mice that aggressively seek food not only can spoil it with their droppings and urine, but they can transmit dangerous bacteria, including Salmonella, by crawling on food preparation surfaces and processing equipment. They also can contaminate raw ingredients that are being stored, along with processed food, by chewing through packaging.

Rats threaten California commercial properties, and it’s important to know which species of rat – Norway rat, roof rat – is present to identify an effective control strategy.

Norway rat burrows are found along building foundations, beneath rubbish or woodpiles, and in moist areas in and around gardens and fields. When Norway rats invade buildings, they usually remain in the basement or ground floor.

Roof rats are slightly smaller than Norway rats, and unlike Norway rats, their tails are longer than their heads and bodies combined. Roof rats are agile climbers and usually live and nest above ground in shrubs, trees, and dense vegetation such as ivy. In buildings, they are most often found in enclosed or elevated spaces such as crawlspaces, walls, false ceilings, and cabinets.

Your rodent inspection checklist

What are the common signs that your facility may have a problem with rodents? Your rodent inspection checklist should include:

Droppings: Droppings and urine are left wherever rodents travel or rest, especially in corners. Identify the rodent type by the size and shape of droppings. Use a palette knife to check droppings — fresh droppings are soft and shiny, while older droppings are gray, crusted and easy to break.

Gnaw marks: Fresh gnaw marks are light and will darken over time. Scratch-like marks on wood, product pallets, etc., approximately 1/16-inch, are made by mice. Clear 1/8-inch gnaw marks are made by rats.

Tracks: Rodent footprints and tail drags may be seen in dusty locations. To view difficult-to-see tracks, shine a strong flashlight at a low angle across the dust. A non-toxic tracking powder, such as a mason’s line chalk, placed on a suspected rodent trail and re-inspected the following day also may assist in identifying tracks.

Rub marks: Rodents leave rub marks from body oil, grease, and dirt along their runways. New rub marks will smear, while old rub marks are darker and may flake off.

Runways: Paths will form between feeding and harborage areas both inside and outside of a facility. Rodents memorize their territory through kinesthetic (muscle) memory and use the same paths repeatedly. Indoors, they prefer to move along walls, shelving units, pallets, and shipping containers. Outdoors, look for dirt paths or beaten-down grass.

Odor and urine: A distinctive, musky odor may be present. Look for urine stains. Rodent urine is visible under black light, but keep in mind that many other commercial products also fluoresce, so don’t rely solely on this method.

If you are looking for a pest management partner that understands your business and can help your company create an effective rodent management program, call Clark Pest Control at (800) 936-3339