News On The Block

Recent press reports of the UK rat population exceeding the human population are likely to be gross over-estimates. More reliable estimates centre on the figure of about 25 million.

The 60 million figure, comes from a estimate made at the turn of the last century (1900) which related rat numbers to cultivated acreage. At that time there were 20 million acres in cultivation and an estimate was made of one rat per acre. The human population around 1900 was about 20 million as well which lead to the rough link of one rat per person.

However, the driver for the link was acreage in cultivation and not human numbers. So, whilst the human population is now around the 60 million mark, the cultivated acreage is similar to what it was a hundred years ago.

Despite this, the one rat per person link has now achieved the status of an urban myth.

What may be driving reported sightings in London is the string of wet summers. Rats are commonly found by water courses and flooding over the past three years may have pushed them from these locations to drier areas where they have come into more contact with people. They can also be found in sewers although extreme rainfall conditions either drive them out or drown them.

In Residential Blocks, it is really important to have defences in place to keep rats out.

This is because once they get in they can do an enormous amount of damage with their teeth. They chew through cables and wires, wooden skirting boards and doors.

They plunder food supplies, contaminating far more than they eat.

They excrete urine and faeces at regular intervals and their urine can carry Weil’s disease (Leptospiral Jaundice) which can be fatal.

Keeping them out usually involves a perimeter of bait stations at ground level to intercept any that wander in from the street or neighbouring gardens.

Additional bait stations are placed near bin areas since the smell of waste food is especially attractive to rats. Planted areas of shrubbery offer cover and somewhere to hide and burrow, so these need to be protected. Sewer manholes can be regularly baited too if it’s possible that rodents could get in that way.

Usually, the basements, boiler and storage rooms and ground floor risers need to be baited so that any rats that find their way past the outer defences are intercepted.

If your block has a persistent problem that never seems to get sorted out, it might be worth getting the experts involved.