Why are cockroaches nearly impossible to kill?


Why are cockroaches nearly impossible to kill?

In: Earth Science

Because they are highly adaptable and reproduce quickly. Meaning they can pass off resistance to their young and continue on through generations with ease

Individually they are easy to kill. Killing the entire group of them you are dealing with is not easy. There is never one cockroach there are always many more you just have not seen yet.

Cockroaches have exoskeletons made up of overlapping plates connected by a stretchy membrane. This membrane is flexible enough to shift the cockroaches’ energy to their legs, allowing them to fit though incredibly small cracks and crevices. Their thick, dense outer layer is able to both protect them and shift and shape when needed.
They can conceal themselves easily in many areas and aren’t deterred by shifting temperatures or other external factors. And while they love to snack on more traditional protein sources, their amazing sense of taste and smell helps them find nutrients in unlikely sources like cardboard or paper.

They aren’t any harder to kill than other insects like houseflies or gnats or mosquitos. However, getting rid of them at home is challenging, because:

* they don’t fly around buzzing, so there can be numerous before you notice them
* they tend to hide in dark places, including cracks and nooks that you don’t even know exist, and are hard to reach. They can hide inside walls if they can access them.
* they breed relatively fast, so if some escape whatever means you use to kill them, they will quickly multiply and become numerous again.
* unlike mosquitos which tend to lay eggs in specific places (like on water), cockroaches lay eggs anywhere.
* they can eat a wide range of stuff, including dead wood.
* they can survive extended periods (up to a month for some species) without food.

Because of these reasons, it’s easy enough to kill **some** cockroaches, but very hard to kill **all of them**, which means that the infestation returns. The best approaches are:

1. long term – there is no quick fix, it will take some weeks or months of care
2. spread by the roaches themselves

The first simply means that because you’re not likely to kill all the roaches in one go, you’ll need to repeat the killing periodically. The goal is to reduce their numbers faster than they can multiply, bringing the population down to zero.

The second means that you’ll likely never reach all the places where roaches can hide, so measures like fumigation or roach baits or sprays will probably not work. But if you can use the roaches to poison other roaches, you gain a big advantage. This is rather easily done because roaches are cannibals, they eat dead roaches. If you can use a poison that stays active inside a dead roach, it will kill many more roaches down the line as they feast on roach corpses.

A good example is boric acid. Its mechanism of action is largely physical, so roaches haven’t been able to develop immunity to it. And it stays active inside the bodies of dead roaches, and continue to kill other roaches that feast on them.

To use boric acid, a two-part strategy often works. First, dust a *very thin* layer of boric acid where you’ve seen roaches walk around before. The dusts sticks to their feet, and is later ingested when they groom. Second, make bait (boric acid + peanut butter in a 1:4 ratio) and put some in little containers (like bottle caps) and leave it around for a few days. Boric acid takes 3-4 days to work, so you won’t see any reduction in number for several days, and it may take a few weeks to get rid of them entirely.

There are professional insecticides that work even better, but all of them will take repeated applications. There is no quick fix to a roach problem other than burning the place down.