An occasional cockroach sighting is not a public health hazard or domestic scandal. But if learning to live in peace and harmony with this particular kind of house guest isn't a project you feel much enthusiasm for, there are ways to reduce their numbers without turning your home into a pesticide bomb.
Even spotless houses can have cockroaches. They can amble in off the street or from (less spotless) neighbouring properties, through cracks or along utility lines.
You could even have unknowingly brought them inside yourself - probably not on your actual person, but in something like a bag or box containing food.
Cockroaches thrive where they have food, water and places to hide, so the first step is to reduce their supplies of these. Remember these insects are generally nocturnal, and like hiding in dark cracks and crevices during the day.
Before reaching for the can of Death to All Arthropods spray, take these simple domestic steps against home invaders first (low-tech doesn't necessarily mean low-effectiveness):
Wipe down surfaces where you prepare food or eat it, and do so immediately after every meal, snack and food spill.
Don't leave dirty dishes out overnight. Or if you must, then give them a quick rinse or leave them to soak in soapy water. Don't leave dirty dishes standing in the dishwasher.
Wash pet food dishes daily, and don’t leave food out overnight. It’s probably better to also empty pet water bowls at night and fill them again in the morning.
Wipe down the stove top every night after cooking. Clean the inside of the oven and the stove hood regularly.
Store non-refrigerated food in glass or plastic containers with well-fitting lids. Clean food storage cupboards/ shelves regularly.
Keep rubbish and compost in closed bins, and dispose of rubbish and recycled materials as often as possible.
Vacuum and sweep regularly to remove food debris. Use the vacuum cleaner’s tube attachment to remove debris and cockroaches from cracks in the wall and floor and behind furniture and appliances.
Regularly clean hard-to-reach areas e.g. behind and under fridges and stoves.
Check for leaks in taps and plumbing e.g. underneath sinks and basins, and get these repaired.
Get rid of clutter. Keep kitchen cupboards as spare and tidy as possible.
Seal up cracks and crevices in e.g. walls and cupboards and around water pipes and electrical lines.
Only when you’ve done all of the above, and the problem persists, should you consider using chemical pest control.
Calling in the big guns
Traps containing glue or bait have the advantage of not spreading toxic chemicals around your home, but the problem with these is that they might trap rodents as well as cockroaches. Glue traps particularly can lead to painful injuries and deaths in small mammals, so try to find out from the manufacturers first if their traps are designed to catch insects only.
There are also pastes and powders available that you can apply to cracks and likely areas such as under the stove. These substances are all toxic (though generally less harmful than aerosol sprays) and should only be used in hard-to-reach places where small children and pets won’t ingest them. Again, you have to consider that you might be killing rodents too. Wear a dust mask if you handle any powders.
Using insect sprays, or calling in professional pest control, should only be used as a last resort. Pesticide sprays are damaging to the environment and your health, and you preferably don’t want them used in your home. Besides which, although these methods may solve your immediate cockroach problem, they won’t necessarily prevent it from happening again in future.
Here are a few non-toxic / low-toxic remedies, definitely worth a try. I must admit I've tried the borax-flour-and-sugar one, to no obvious effect. Let me know if any of these work for you, or if you have your own secret recipe you're prepared to share:
- Squashing. I know, I know. Only for the lion-hearted. Spraying them with water first can slow them down.
- Sprinkle borax (available in supermarkets) in cockroach-popular places. The cockroaches lick it off their feet, die, other cockroaches eat the dead ones and die also. Or mix borax powder with flour, sugar and some water to make into a paste. Borax is much kinder to the environment and much less toxic than commercial pesticides, but it is toxic nonetheless, so you can't paste your paste anywhere that a pet or small child might be tempted to try it. To avoid that, you can put your paste inside a container / bottle / can that has an opening only big enough to allow cockroaches access.
- Rub the inside top part of a glass jar with vegetable oil and place something tasty like fruit (my cockroaches fancy nuts) inside. You can make a "ladder" by propping e.g. a piece of wood / cloth against the outside of the jar to facilitate access. They get in, but can't get back out because of the slippery oil. You don't have to squash your captives - apparently you can put them in the fridge to freeze to death. I'm a bit dubious about that because I've found cockroaches in the seal of the refrigerator door... though maybe that partially protects them from the cold.
- A small tub of water with a squirt of oil in it can attract cockroaches who'll climb in and drown. Apparently.
(Olivia Rose-Innes, EnviroHealth Editor, Health24, updated February 2012)