Construction sites are often an irresistible attraction to the local rodent population – especially in winter. David Cross, head of technical training at Rentokil Pest Control, offers some advice.
Construction professionals are highly trained to identify health and safety threats, and operate in a way that mitigates them. Nevertheless, while objects that could cause slips, trips or falls are quickly swept up, pest problems on sites – specifically rodent infestations – often go undetected or untreated for a significant length of time.
Construction frequently disturbs locations where rodents are already present. On greenfield sites, rats will often already be resident or habitually moving through the watercourses. When these sites are disrupted, it is very likely there will be movement within the rodent population. As construction sites become more established, with workers bringing in food, the site becomes even more attractive to rats and mice.
Brownfield plots present their own unique set of problems. Construction on these sites often involves connecting to existing drainage systems, enabling any rodents which may be in them to access the area. Disturbing flagstones and demolishing old buildings – which may already harbour pests – can also cause problems. Again, as these sites become more established, they become more attractive as they offer shelter, warmth and a regular food source.
Issues can also arise as buildings are typically pest-proofed only as they reach completion, which means that weak points may not be addressed at the design and planning stages. In particular, poorly designed wall cavities can offer perfect harbourage for rats.
How can flooding compound the problem?
While construction sites are always prone to rodent infestations, they are more common in winter months, when falling temperatures drive rats and mice to seek warm harbourages and food sources.
This coincides with the period when construction sites are frequently left unmanned, as workers head home for the festive period or poor weather puts works on hold. As a result, pests can move in and, left to their own devices, make themselves well and truly at home.
Severe weather compounds this problem further. December 2015 was the wettest on record, and many areas in the north of England suffered severe flooding. This can increase pest populations in construction sites due to the added disruption caused to their natural environment. Water infrastructure on the site, already a point of entry for rodents, is also placed under additional strain. Any breaks or faults in pipework widens the door for rodents, making the site even more accessible and welcoming.
Why is pest presence such an issue?
Rats in particular pose a real health risk to those working on construction sites and residents in properties nearby, as they are prone to spreading leptospirosis through their urine. This can be compounded in wet conditions, as the bacteria can survive outside the rodent’s body for longer periods. Humans can catch the disease through exposure to rodent urine within the water and soil that comes in with floodwaters, and through shared food sources.
In most cases the bacterial infection manifests itself through mild flu-like symptoms such as headaches, chills and muscle pain. But in more severe cases it can lead to Weil’s disease, which can induce more life-threatening problems, including internal bleeding and organ failure.
For these reasons, it’s imperative that construction workers adhere to high hygiene standards. Taking the following, basic precautions, will dramatically reduce their chances of falling ill with a nasty infection:
- Cover all cuts and grazes with waterproof plasters to prevent contaminated water entering directly into the bloodstream;
- Wear waterproof clothing, including gloves, to prevent exposure through contaminated water and soil;
- Do not swallow contaminated water;
- Wash and dry hands before eating, drinking or smoking;
What can developers do to minimise pest presence?
A of lack understanding around the key signs of pest activity can be a major issue on construction sites. It’s therefore a good idea to involve a pest contractor at the early stages of a project, so that they can monitor for pest activity while construction is taking place. A pest technician will be able to pay particular attention to the perimeters of the site, to minimise pest entry and movement.
As construction starts, any harbourages need to be carefully monitored – as do areas where workers will be consuming food and drink. Having a tidy site is critical for meeting health and safety regulations and deterring pests.
Before a building reaches completion, I would also strongly recommend that a final pest check is undertaken by a fully qualified technician to ensure all gaps are filled in and the possibility of future rodent harbourages is minimised.
