Rats are a highly successful species which survive the winter months very well, but as the weather becomes colder, they often need to utilise human resources to do so. As such, rat infestations can become a vermin problem for facility managers during the cold winter months. This is especially so during a COVID age where facilities may be being used less than normal being somewhat left to their own devices, dormant. Perfect for a rat looking for winter shelter.
Why do rats look for shelter?
As the autumn, as vegetation dies back and the availability of food sources such as fruits and nuts decreases, rodents will look for new shelter and above all, new food sources. In turn, this leads to rodents living in empty buildings, outbuildings, sheds, wall cavities, cellars or between floors - anything with a structure that they can live underneath. Both rats and mice can survive in wall cavities without even leaving, as they will feed on insects, woodlice, and can extract the moisture they require from their food or from winter condensation on pipes.
If a mouse comes across an area of high food value such as a food store then their territory size will shrink. Territory size is very important when treating mice, and the focus of vermin prevention with mice is the correct identification of their territory (with a survey) followed by appropriate measures to rectify the problem in the aforesaid territory.
Rats though, tend to be more food orientated. Rats will look for shelter first, then venture outside to find food sources, typically homing in on any rubbish or compost maintenance areas. With consumers, this usually means the bins, the bird feeding area and the compost heap - all notorious areas of food spillage that provide an easy meal for rodents. For business, the rubbish area is again the principal area of focus, especially with hospitality venues that have a high turnaround of rodent-edible foods on offer.
Unlike mice, rats are neophobic - suspicious of anything new placed within their territory. So whilst mice will actively explore new objects and can be lured by actually moving traps about, rats are the opposite - they treat anything new with grave suspicion. This can make rat control with baits and traps challenging for the non-professional.
Signs of a winter rat problem
As we approach the coldest time of year in the UK, it becomes important for facility managers to be aware of the signs of a rat infestation, as the rodents will now be looking to set up shelter from the cold. Look out for the following signs:
- Holes in the ground protruding from structures with foundations. Typically two inches across with a sizeable scrape of mud protruding, rats burrow under structures such as foundations, decking and sheds/outbuildings, but also require exits to access food sources.
- Signs of nesting: shredded materials, including paper, cardboard, plants, rubbish, wood shavings and timber gnawings
- Damage to property, food stores and rubbish areas. Rats have to chew on hard materials to keep their incisor teeth small and sharp, so keep an eye out for gnawing marks on walls, wood, surfaces and even metals. Rats have to gnaw in order to keep their teeth in shape, and frankly they’re not shy about what they gnaw on.
- Bin bags will be torn open as rats and mice hunt for food and nesting materials, and food stores especially grains and cereals will be a particular target for obvious reasons.
- Droppings: Rat droppings are elongated, the size of dark brown rice and relatively easy to spot, so be sure to check for them.
- Scratching: Rats will set up residence in walls, under floorboards, sheds and decking, and even up in the roof. They are remarkably competent climbers, and are usually noisy and audible, scratching around, especially in the evening and at night.
- Footprints and rubbing marks - perhaps in your lesser used areas where there is a build-up of dust, you may be able to make out the footprints and tail marks where rats are present. Skirting boards are also worth a check, for grease marks, as filth on rat bodies can leave smudges along the surface.
- Food stockpiling
Food stockpiling for winter
In the wild, food becomes scarcer in the winter months. Rats know this and make preparations, usually by stockpiling food for the coldest winter days ahead. Rats don’t hibernate and have too small a stomach to fatten themselves up for the winter. Rats will nevertheless prepare for imminent food shortages in other ways. In late autumn, rats start hunting for food with extra purpose, and rather than eating everything, they start stockpiling for later consumption.
Rats will eat pretty much anything. In the wild, they often feed on fruits, grains, seeds and other vegetation. But they are not picky. When these items are off the menu, they’ll turn to insects, smaller animals and even their own faecal matter if times are tough. But of course, the main reason why rats are such a vermin problem for humans is that many will make an almost exclusive living off human waste and rubbish. As winter approaches, rat activity around rubbish areas can increase as the rodents begin scrounging for food waste to hide away for later consumption.
Winter nesting preparations
Unfortunately, once rats have chosen a building in which to shelter from the cold, they will next turn their attention to building a nest. Rat nests not nearly as organised as bird nests are - rather than carefully weaving together twigs, leaves and feathers as the birds will, rats simply make a rough pile of shredded materials – plant materials, but also materials such as cardboard, insulation and any other soft rubbish they can find, bunching it together.
The fact is, for rats, it’s the location rather than the materials the nest is made from which matters most. They prefer warm, dark places that are free from predators – and again, as relatively disused man-made buildings will provide such spaces, rat infestations can become a particular pest control problem in winter.
What should I do?
The best method of rodent control is prevention through sanitation and exclusion. These highly successful, intelligent creatures can enter buildings and facilities through spaces much smaller than the seeming width of their bodies, and it is important to keep an eye out for signs of mice and rats and understand control methods.
Usually, it is more productive to call on professional vermin experts, and this is especially true if the pest problem is ongoing, if the infestation has become large, or if the products needed for control are only authorized for use by certified professionals. For advice, a vermin survey or vermin treatment, please call GRITIT on 0330 100 2811