Thigmotaxis

That's a fancy word. But it is an important word to know if you want to understand why it is hard to get all the cockroaches out of your home. Thigmotaxis is a behavior that causes an organism to want to get into tight spaces. When cockroaches explore the outside of your home, they don't know that there is food inside. The reason they get in is that they are drawn to explore every tight space, even spaces that are so small that you might miss them during an inspection. This makes it extremely difficult to completely seal cockroaches out of your home. So, even if you're able to exterminate all the cockroaches inside your home, more roaches are likely to get in and replace the ones you've killed. They're just doing what comes naturally. But keep in mind that this doesn't mean you should try to seal entry points in your exterior. It is just important to understand that exclusion, by itself, is rarely enough.

Mobility

Cockroaches are incredibly mobile. They can scale walls, run across ceilings, and some species have the ability to fly. If you have a tiny opening in your roofline, these insects are able to get up there and find it far easier than you are. This ability to get around quickly on vertical surfaces, combined with their love for tight spaces and ability to compress their bodies to fit into spaces half their height, make roaches difficult to keep out--which makes them also difficult to exterminate.

Resistance

Cockroaches aren't just difficult to keep out of Streator homes, they're difficult to eliminate with conventional treatments. If you spray a cockroach, you could kill it. But a roach that crawls across a surface you've sprayed can survive. If it is a cockroach nymph, it is able to shed its skin and create a new one that is more resistant to that particular chemical. That means it will not only be tolerant to walking over areas that have been sprayed, but it will be able to take a direct spray. We strongly discourage the use of over-the-counter sprays to eliminate roaches because cockroaches that become immune to these chemicals can spread them to your food-storage areas, dish cabinets, silverware drawers, and food-prep surfaces.

Why can cockroaches survive contact with chemical sprays at all? They have an impressive immune system. Their immune system helps them survive exposure to many things that would kill a human, such as radiation, pathogens, bacteria, and parasitic worms. Since the dawn of time, cockroaches have been crawling around in sewers, on dead animals, in trash heaps, and other disgusting places without injury. Modern roaches are even stronger. Studies have shown that pest cockroaches, like the German cockroach, are born with chemical resistances that have been passed on to them. Licensed professionals understand the challenge that this presents, and they use a combination of EPA approved products and field-tested methods to get the job done.