Where Barnet's Rats Come From
Everything you will meet in a Barnet property is one species, the brown rat. What varies is the road it took to get there, and identifying that road is the whole job — a treatment that leaves the route open is a treatment you end up buying a second time.
Along the brooks
Dollis Brook, Silk Stream and Pymmes Brook run in the open through much of the borough, and rats travel watercourses. If your garden backs onto one — in Whetstone, Totteridge, Mill Hill, Friern Barnet or along the Dollis valley through Finchley — you can have persistent rat activity with nothing whatever wrong at your own property.
This is the part people find hardest to accept, and it is worth being plain about it: no drain repair will touch a brook-corridor problem. What matters there is what is drawing them up the garden and where they are getting into the building, which is a different job from a drainage fault.
Up through the drains
In the older terraced streets at the southern end of the borough — Childs Hill, the fringes of Golders Green, parts of East Finchley — the usual explanation is the one that applies across inner London. A cracked pipe, a displaced joint or an old connection left open under a kitchen extension lets rats out of the sewer and into the ground beneath the house. Activity under a floor with no visible hole outside points this way.
In from gardens and the green edge
Barnet's suburban gardens are long and many back onto allotments, playing fields, golf courses or open land at Totteridge, Arkley and Mill Hill. Rats burrow under decking, shed bases and compost bins, feed on bird food and windfall fruit, and then find a gap around a pipe or a perished air brick.
Signs of rats
- Droppings the size and shape of a large grain of rice, dropped in loose clusters
- A dark, waxy band low down where they run the same line along a wall or pipe
- Chewed edges on skirting, packaging, pipe lagging or cable sheathing
- Heavy scratching overhead or beneath the floor once the house goes quiet
- Fresh soil fanned out from a hole beside a shed base, a path or the brook bank
- A sour, ammonia-like smell building up in a cupboard or understairs space
Stopping them coming back
The treatment clears the rats in the building. Whether they stay gone depends on the route. A drainage fault is a job for a drainage contractor, found with a camera survey and closed with a repair or a one-way blocker. A brook corridor cannot be closed at all, so there the work is removing what draws them up the garden and sealing the building itself. Either way, the accessible gaps are what our rodent proofing deals with.
