How Do You Know If You Have Cockroaches in Greenwich?

Time of Day Changes Everything

Cockroaches are nocturnal and they avoid open space. A population that is comfortable stays in the warm voids and comes out after dark, so seeing one means something specific about the state of the population.

So the alarming version is not the one you saw at midnight. It is the one you saw at three in the afternoon.

Where You Were Standing Changes the Species

This is the second question, and it decides what the treatment will be.

Warm parts of a kitchen - behind the fridge, around the cooker, inside a unit, near cabling - points at the German cockroach. Small, pale brown, lives inside the warm structure, breeds quickly, and in a block moves between flats through service risers.

Around a drain, a gully, a bin store, a basement or a lower ground floor - and usually larger and much darker - points at the Oriental cockroach. It prefers cool damp places and its origin is generally outside the room you are standing in.

You do not have to be certain. Telling us where and when you saw it usually separates them before anybody arrives.

The Other Signs, and What They Are Worth

1. Droppings like ground pepper. Small dark specks in cupboard corners, along the tops of units, behind appliances and in the runs between them. Good evidence, and the distribution shows you where the harbourage is.
2. Egg cases. Small, dark, ridged capsules glued into a crevice or dropped near harbourage. Very good evidence, and it means breeding rather than an arrival.
3. A smell. Musty and slightly oily, noticeable when a cupboard has been shut. Suggests a substantial population; its absence proves nothing.
4. Shed skins. Pale, empty and cockroach-shaped, usually near harbourage.
5. Smear marks in damp areas. Irregular dark marks where insects travel over wet surfaces.

What Else It Might Be

Cockroaches are misidentified more than almost any other pest we are called about, and the mistakes go in both directions.

• Ground beetles from the garden. The commonest false alarm by some distance, particularly in ground-floor flats with a door open in summer. Hard-shelled, rounder, and they blunder about rather than running for cover.
• Crickets. Long back legs, and they jump. Cockroaches run.
• Beetle larvae in a food cupboard. A stored product problem rather than a cockroach one, and treated completely differently.
• Coffee grounds or cocoa in a drawer, mistaken for droppings. Droppings are uniform; spilled grounds are not.

What to Check Tonight

Fifteen minutes with a torch, after dark, with the lights off until you are in position.

1. Go into the kitchen in the dark and switch the light on. If there is a population, this is when you see it.
2. Look behind and underneath the fridge, which is the warmest and most sheltered place in most kitchens.
3. Check the underside of the worktop and the top edges of unit carcasses with the torch, looking for droppings and egg cases.
4. Pull out the bottom drawer and look into the void behind it.
5. Look around the dishwasher and washing machine, particularly where the pipework enters the wall.
6. If you have a basement, cellar or utility area with a drain, check it separately - that is where the other species lives.

It Says Nothing About Your Kitchen

Cockroaches need warmth, moisture and small amounts of food, all of which exist in a spotless kitchen. In flats they very often arrive from elsewhere in the building entirely - through a service riser, a shared void or the gap around a waste pipe - which means the property's own housekeeping had nothing to do with it.

Worth saying because embarrassment delays calls, and with cockroaches delay is expensive: the population grows quickly and a problem that spreads into neighbouring flats becomes a much larger piece of work.

When to Call

• Any daytime sighting.
• Droppings or egg cases found anywhere.
• More than one sighting, on separate days.
• Any sighting at all in a food business.
• Neighbours in the same block reporting the same thing - that changes the job from a flat treatment to a building one.

If You Run a Food Business

The threshold for acting is different and the record matters as much as the treatment.

• A single sighting is enough to act on. In a domestic kitchen it is reasonable to check for other signs first. In a food business it is not - the cost of being wrong is not comparable.
• Keep the specimen. Species identification determines where the work goes, and a confirmed identification on file is worth having.
• Record what you found, where and when, along with what you did about it. That record is frequently more useful afterwards than anybody expects.
• Tell us the type of premises at the enquiry, along with where the sightings are and what the constraints are on timing.

Equipment housings, the voids between units and the space behind stainless steel are the usual harbourage. Access to them is what determines how much of the population a visit actually reaches, so the preparation matters more in a commercial kitchen than anywhere else.