Rodents in New Zealand Supermarkets: Understanding the Issue

Tuesday 13 February 2024, 6:45PM

By ACES pest control


help mice!
help mice! Credit: ACES pest control

Rodents in New Zealand Supermarkets: Understanding the Issue


Rodents in supermarkets. Recently, the media has brought to public attention two examples of rodents inside supermarkets. Pest control in supermarkets, in both cases, they were in the deli, contaminating the food. How can this be? It seems impossible! Is the supermarket at fault here? Or is their pest control company incompetent? Or is there a Rodent infestation in NZ, and this should be expected?

Exploring the Challenges of Supermarket Pest Control

Supermarket hygiene. We all know the two main chains of supermarkets in New Zealand, and we are all impressed with their professional and super clean appearance in the shop front. What the members of the public do not see is the other side of the business: the entrance way(s) and warehouses are extremely busy and packed areas. Members of the public do not understand that, to maintain stock on the shelves with the checkout constantly selling items, you need almost constant deliveries too. Imagine a service dock out the rear, with trucks coming and going, dropping off hundreds of boxes of items to replace those sold by the checkouts. Yes, they have staff to clear them, but sometimes the loading bay is crowded, and sometimes it works 24 hours, or at least late into the night. This is important for pest control, as one of the critical areas for rodent control is access points. Here we have the main access point to the warehouse open when nocturnal rodents are active. Also, the volume of these supermarkets is high, so often there are many piles of boxes, allowing rodents to enter (and leave) without being seen. Then there is the warehouse, again unseen from the public. Large storage areas of shelves piled high with food, glorious food. Not just the boring stuff, but the yummy stuff too like chocolates and nuts. Added to this, these shelves and stock are perfect hiding areas for rodents. They get around a warehouse behind the shelves without being seen for the most part. Also, these busy businesses have some food wastage. Even if they dispose of this correctly and the rodents can't gain access, they can smell it. That brings them onsite, and then there’s that warm and dry warehouse waiting with its doors open all hours to welcome them in. The three important key sites to find for rodent control are their nests, their trails, and the access points. Immediately we have access points we cannot close off. And trails that are very difficult to get to on account of the stock and the way it's stored. Supermarket pest management given an established rodent population inside the business, it’s difficult to control.

Factors Contributing to Rodent Infestation in Supermarkets

Rodent control measures. For all the reasons listed above, this makes for a tough job. But there are professional companies that have plans for this. Yes, you are correct. However, food businesses present challenges to any pest control company, as they render bait less effective. Bait is the main tool worldwide for the control of rodents. Why is bait less effective in supermarkets? Because rodents have a keen sense of smell, and quite quickly, they are in the deli counter helping themselves. Bait stations are a distant memory as they tuck into the excellent food in the deli. Further, remember that loading dock. Well, not only is it open all hours to all rodents, but there is often so much stock on it that exterior stations are practically useless. Sometimes adjacent properties can have rodent issues e.g., streams/parks/vacant houses/businesses that can bring rodents right to the doorstep of these businesses.

Is the Supermarket to blame?

In my experience, the operators of supermarkets have their own pest control programs, and often have one or more Professional Pest Management companies working with them. So that’s a definite NO to that one.

Strategies for Effective Rodent Control in Supermarkets

The first thing needed is an inspection to work out where are the rodents nesting sites, access point for rodents, and rodent trails. Once you have this information and understand the situation, you can use controls to decimate the population. Bear in mind it takes time. Why? Because rats are about as smart as your cat or dog and understand that we want to kill them. You need time for them to get used to the controls. As bait is probably off the menu, rats need up to seven days before they trust a control like a trap to come near it. Good things take time. This is why one the Supermarkets has extended the time the business is closed.


Rodents that are established in supermarkets are a tough job. I am certain that the companies involved are working professionally to resolve the situation as soon as possible given the difficult conditions.