Mice
How Mice Move Around a Mansion Block
Older blocks were built with timber joists resting in thick brick walls, and the void between each ceiling and the floor above runs across the whole flat. Where a joist end sits in a pocket in the wall, or pipes pass from one flat to the next, those voids connect sideways as well as up and down. A mouse nesting behind the kitchen units on the second floor can forage in the first-floor flat and the third without ever being seen on the stairs.
Boxed pipes and old flues
Heating, water and waste pipes have been added to these buildings over many decades, usually hidden in a timber box running up the corner of a kitchen or bathroom. Behind the box there is often a gap where the pipe passes through each floor. Disused chimney flues do the same job on a larger scale, and a fireplace that was boarded over rather than properly blocked can let mice move between floors. Where mice nest looks at the hidden spaces they pick.
The common staircase
Mice also use the shared parts of a block. The cupboard under the stairs, a store room off the entrance hall, the gap beneath a flat's entrance door and the space behind a radiator on a landing all give cover. A worn door bottom on a ground-floor flat is an easy way in from a stairwell that mice already travel.
Signs in a Period Flat
- Droppings behind the pipe boxing or inside the cupboard where pipes come up through the floor
- Scratching in the ceiling that seems to come from the flat above
- Nibbled packets in a cupboard built into an old chimney recess
- Droppings on the floor just inside the front door of the flat
- Grey smear marks along the skirting where it meets the wall
The signs of mice guide goes into what each of these means. Larger droppings, or noise under a basement floor, may point to rats from the drains instead.
Tell the Building as Well
Because mice in a block rarely belong to one flat, it helps to ask your neighbours and to tell the porter or managing agent. Can mice travel between flats? explains why treating one flat alone may not hold, and the Childs Hill area page covers who normally looks after the common parts.
What to do now
- Store dry food, cereals and pet food in sealed tins or hard plastic tubs
- Clear out the cupboard around the pipe boxing so droppings are easy to spot
- Keep your flat's entrance door shut, and ask the agent about a worn threshold
- Do not seal gaps yet: a mouse shut inside a floor void will chew another way out
Booking and preparing
When you book mouse control, tell us which floor you are on, whether other flats have noticed mice, and which rooms the signs are in. Before the visit, clear the cupboard under the sink and the space in front of the kitchen kickboards so they can be reached.
After the visit
You will hear what was found and what to expect next. The time it takes depends on the flat and how far the mice reach through the building, and how long mouse treatment takes explains the factors. Get in touch again if droppings reappear after things had gone quiet.
Keeping Mice Out of an Older Flat
Once activity stops, the gaps around pipes where they pass through floors and walls are the ones to close, along with any boarded-over fireplace that is not properly sealed. Small accessible holes inside your flat can be done with rodent proofing in Childs Hill. Why mice keep coming back explains the pattern, and Mouse Control Barnet covers the rest of the borough.
