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  • Writer's pictureChelle Hartzer

Houston, We Have Problems (AKA: Didn’t see that coming)

I usually don’t get called until a pest issue is fairly bad. It’s been going on for months, (if not years), it has not been getting any better (or it’s been getting worse), and multiple things have already been tried (hopefully). There are typically two questions: “we never had this problem, why do we have it now?”, and “why isn’t it getting better?” So many different answers to these questions depending on the situation. Let’s take German cockroaches as an example.


German cockroach adult
Sneaky little cockroaches

First, cockroaches are small, sneaky, and nocturnal. Most people don’t notice any issues with German cockroaches until they are running around the kitchen floor and they see them. Unfortunately, this is after populations have built up and the chance of seeing one out of ten thousand is a lot greater than seeing one out of ten. There are just more of them out foraging. When populations are big enough, they start foraging during the day too. Think of this from another perspective: a spider gets in and sets up her little home in the corner behind the desk. You don’t see her, she’s small and only needs to eat a few little insects every so often. But she’s also carrying an egg sac. When it hatches, you know have 300 little spiders all running around looking for food. It’s not until the numbers have increased, over months and months, that a problem is finally noticed visually.

German cockroach nymph
Sneaky LITTLE cockroaches!

German cockroaches are masters at hiding. Estimates are that the average population of these cockroaches is around 20% adults and 80% nymphs. This means that less than a quarter are fully grown. Those little nymphs: even harder to see than adults. Also, German cockroach nymphs tend to hide better than adults do. In fact, there are some estimates that they do not come out of their hiding spots at all until they are nearly adults. How does this work? Since these cockroaches live in close contact with each other, almost as a colony, the adults bring back little pieces of food stuck to their legs and bodies. They also exude what is basically cockroach sweat the nymphs will feed on. One more food source: nymphs are coprophagous, they eat feces of the adults. So if you are a tiny little insect, in a safe and warm hiding spot, with food delivered on a regular basis, why would you come out? The population continues to build up in that wall void behind the stove until it is thousands if not millions of individuals.

German cockroach nymphs on glue board
Monitoring = good. Placement = better!

But you are smart, you have monitoring devices placed so there’s an extra set of “eyes” on finding these early. This doesn’t guarantee finding them. Monitors, specifically glue boards, often get placed in areas that aren’t going to have cockroaches. Or they may not be near cockroach hiding spots. Placing these on top of the fridge or under the stove is going to have a better chance of catching cockroaches than in a linen closet or office space. Glueboards often need to be in hard to reach areas that someone a person can’t get to easily. This means they can easily get forgotten and ignored. So the cockroaches go on doing their cockroach thing.


Behind fridge - customer never saw one

But you looked and didn’t see anything! Remember they hide and are nocturnal. In one study of apartments, 50% of the residents didn’t know they had a problem. These are residents that live there so someone is in that space daily. Even for professionals, inspections can miss places. Some areas can be excessively cluttered, have sanitation issues, or are behind locked doors that can’t be accessed. I had a situation where we inspected a large facility that was having German cockroach issues. We had it narrowed down to employee areas: kitchen, breakroom, locker rooms. The area was deep cleaned (you wouldn’t believe what was behind the vending machines…ugh), treated with multiple means, and saw numbers quickly go down. They didn’t stay down, our monitors and inspections started to show increases again. Turns out, the individual lockers were never cleaned and emptied and because we didn’t have keys, we couldn’t get in to inspect each one. Once this was discovered, the issue was addressed (employees were not allowed to store ANY food in their lockers from then on), and we had the problem under control.

Watch them scatter!

Aside from the harborages they can take advantage of (ever move that board outside and see all the insects scurry out from under it?), there are all the hidden sanitation issues that provide food. While German cockroaches may be one of the most common structural pests, other pests utilize the same survival strategies. Think of mice hiding behind a freezer and tunneling into the insulation, or small flies living in a dirty drain, or fruit flies on that one potato all the way in the bottom of the bag in the back of the drawer.


It’s not hopeless though. Having a solid preventative plan in place and knowing what to look for, how to look, and where to look can help minimize large infestations. Catching these issues when they are still small means they can be contained and treated faster and more effectively. Have you been dealing with a tough issue? Want to know more about implementing preventative plans? Contact us here!


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