Found this helpful post on my local Mums FB page. I can't take credit for this awesome information.
Hello, I’m your friendly neighbourhood entomologist (insect scientist). A sure sign of summer is the increase in everyone’s favourite insect….cockroaches! So by request, I’ve posted some tips about what to do when you start to see these animals in our home (and I’ve hidden some fun facts in there as well😊).
Roaches are awesome. Seriously.
I know , I know- most people hate cockroaches. Which is too bad because they are fascinating and beautiful animals. The small number of species that become pests in our houses are not representative of these amazing animals. Cockroaches play a key role in our ecosystems- they are basically nature’s waste management squad. Bush cockroaches help to break down plant matter and rejuvenate soils. See the roach facts at the end of this post for some seriously interesting facts about our little six legged cleaners. I’ve put picks of some beautiful cockroach species in the comments- have a look!
I saw a roach. Should I spray?
Probably not. Cockroaches are a normal part of living in Sydney. We are lucky to have wonderful warm weather; cockroaches are simply part of living in a subtropical climate. There are 450 species (types) of cockroach in Australia of which only five are considered pests. The larger species are less likely to become major infestations indoors and are often entering from outside. Seeing the odd one here and there is not generally a problem.
The smaller light brown/tan species (often called ‘German cockroaches’ despite not being from anywhere near Germany) can breed very quickly so I tend to be more proactive when I see them around my house.
So, how many cockroaches are too many cockroaches?
Bottom line: if you see one or two big cockroaches I wouldn’t really worry; they likely wandered in from outside. If you start seeing more than a few indoors within a 24 hour period, then it’s worth starting a management plan (see below). If you see one or two little tan German cockroaches, go to step 1 below and follow the plan.
Do cockroaches pose a risk to my health? Do they carry disease?
In low numbers, cockroaches are not a major threat to your health. Cockroaches are what we call ‘mechanical disease vectors’. This basically means that they can move bacteria around if they come into contact with it (mostly gastrointestinal stuff).
For a cockroach to transmit a disease to you, it would need to first walk through a contaminated area (raw meat, faeces) and then happen to walk over uncooked foods like salads, or across a food preparation area. In practise, this is likely not a problem in most households. The exceptions are places like aged care facilities, hospitals and food preparation spaces where there is an increased risk of cross contamination. The risk of contamination can be greatly reduced simply by practising good food hygiene (not leaving raw meats out, cleaning surfaces, food preparation utensils and cutlery).
Allergies to cockroaches are relatively common, especially in asthmatics. For allergic people, exposure to cockroach-associated allergens can result in hay fever-like symptoms, similar to dust allergies. However, cockroach allergies tends to become a problem when cockroaches numbers are high. If you have a known allergy to cockroaches (an allergist can test you) then it’s more important to keep cockroach numbers down. For the rest of us, cockroaches are a pretty minor concern.
Ok, I have too many cockroaches. What should I do?
Time to enact our management plant. One of the central ideas behind sustainable pest management is using the least toxic/expensive techniques first. Only escalate to the next step if the pervious step hasn’t worked.
Step 1: Prevention (do this all the time, even if you don’t have a problem).
Cockroaches come into our houses because we provide two things they need: food and humidity. So step 1 is to try to make our houses less cosy for them. Make sure all food is sealed in containers, including stuff in the cupboards (like boxes of crackers, bags of sugar). Don’t leave food out over night- this includes fruits, bread, butter, etc. If you have a cat or dog, don’t leave their food bowls out overnight-roaches love pet food. Also make sure all pet food is stored in sealed containers.
Consider emptying your bins outside each night before bed as roaches can easily get into most kitchen bins. Or invest in a bin with a nice, tight seal. Make sure to clean behind the fridge, empty crumbs from the toaster and check in between cushions (because that is inexplicably where my kid seems to stash food). Remember that having cockroaches doesn’t necessarily mean you have a dirty house – they are just very, very good at finding food. Your goal is to make it that much harder for them.
Next, try to seal up any cracks in baseboards, walls or around bathtubs. Roaches (especially the little German roaches) like to hide in small dark spaces. They also need high humidity, so pay special attention to areas around bathtubs and sinks. Look for small black/brown specs that look like dirt clustered around bathtubs and sinks- this could be cockroach poop (called ‘frass’).
Leaky faucets or pipes can provide much-needed humidity for roaches. Check drains and clean if necessary- sometimes roaches can live off of food trapped in sinks. Seal up cardboard craft supplies as roaches like hiding in between bits of cardboard. Try to reduce clutter as roaches like living in small dark spaces.
If you have a small number of roaches, either escort them outside (preferred) or squash them. Vacuums work too, but make sure you empty the bag outside (or pop it into the freezer overnight to kill the roaches). Avoid using sprays; they can be effective, but I ‘m generally not keen on spraying insecticides around a house if not absolutely needed. Used as recommended on the label (always read the label!!), most commercially available insecticides are safe for humans in low doses , but I don’t think even the tiny risk is worth it given that you can just squish or vacuum them for free.
STEP 2: Insecticidal Baits
If you’ve locked up your food, eliminated nesting habitat and done the best you can to clean away crumbs, and you are STILL seeing too many cockroaches, then it’s time to move to step 2: insecticidal baits. Insecticidal baits are a more environmentally friendly and safer way to go as the insecticide is contained within the bait and will only effect insects that eat it.
The best baits come in sealed plastic boxes, so that only a small insect can access the bait. The trick with these is to place them in places where cockroaches are likely to be. Roaches tend to walk along walls, so put the baits flush with walls. Place them in bathrooms, under coaches, around bins and anywhere you may have noticed high numbers of cockroaches. Write the date on the bottom so you know when to replace them (most baits only last 3 months-ish). As many baits are neurotoxic (to insects) you might see distressed twitchy roaches around – please don’t toss these outside as we don’t want other insects to eat them and become ill. Departing roaches can be put in the bin outside to minimise the chances of something else eating them.
STEP 3: Call for help!
If you’ve tried cleaning and baits and you still have a problem (you’re still seeing several roaches per day), then I recommend calling a good pest controller. The home pesticide options (bug bombs, sprays) often don’t work well when you have a real infestation. A professional will know which products are best for your particular situation. Don’t be afraid to ask lots of questions- not all pest controllers are equal.
I strongly recommend against regular pest control sprays (for example, routinely getting pest control in to spray the house every spring). First, there’s no point spending money if you do not have an issue. Second, regular spraying in the absence of a problem increases the risk of insects developing insecticide resistance. Once that happens, controllers will need to start using more toxic sprays in order to have an effect.
Here are some fun cockroach facts:
- Some cockroach species look after their babies for up to 9 months, carefully feeding and cleaning them. Other species feed their young with a special substance they secrete from their body- just like milk! Who knew that cockroaches were such caring mums?
Cockroaches can live for up to a month without their head!! They can do it because they have bundles of nerve tissue called ‘ganglia’ that act like mini brains throughout their body. So if they lose their main brain, the mini-brains can still preform most of their functions. They have light sensors on their legs, so they don’t need their eyes to know when you’ve turned the light on and it’s time to run in an erratic and disconcerting manner. They breathe through holes on their sides (called ‘spiracles’), so no need for a mouth or nose!
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- The world’s heaviest cockroach species is the giant burrowing cockroach. They live underground in Queensland and can live up to 10 years. I have an 8 year old pet burrowing roach named ‘Skelly’.
Cockroaches come in a variety of colours and patterns, including some absolute stunners. See the pics in the comments below for some beautiful roaches.