How to Kill Cockroaches
You’ve probably seen cockroaches before, but were likely too concerned with screaming, running away, and finding a can of Raid to notice much about the bug. There are many, many different types of cockroaches, and every variety has its own unique set of characteristics and habits. It’s definitely possible that your area is inhabited by a number of cockroach species, so you’ll probably need to use a combination of pest control methods to battle all the different cockroaches that want to share your home.
In general, cockroaches are an incredibly hardy group of insects, which is why it’s so hard to kill them. They’ve evolved over millions of years to become resistant to as many threats as possible, and because they reproduce extremely quickly, different species can sometimes develop resistance to specific pesticides.
Most types of cockroaches can survive a month without water and two to three months without food, which make
s it difficult to get rid of the bugs simply by depriving them of nourishment. And if you’ve ever heard that cockroaches can survive for long stretches of time without their heads, you heard right. Because cockroaches don’t breathe through their mouths but rather through openings (called “spiracles”) all over their bodies, the head is not crucial for the roach to survive for a few days; it’s only necessary to allow the roach to drink water or eat food.
Here are some tips on eliminating those crafty cockroaches from your apartment, and preventing the bugs from coming back.
Eliminating roaches with ease (okay, maybe not too much ease…)
If you see roaches in your apartment on a semi-regular basis, you’ll probably want to enlist a professional, or ask your landlord about getting your apartment professionally treated. This is probably the best—and possibly the only—way to eliminate any significant roach population in your apartment. Your do-it-yourself treatment options include the following, in rough order of increasing toxicity. Homes involving pets or small children will probably want to keep to the first few, less toxic, options.
Live traps
Live traps work by attracting the cockroach to the trap with some form of bait. You can purchase live traps or make your own 
using a bowl with steep sides. Put petroleum jelly on the inner walls of the container so the cockroach can’t climb back out, and then put food and damp paper toweling at the bottom of the container. Make a paper ramp leading into the container so the cockroach climbs in due to the food but is unable to escape due to the petroleum jelly barrier. After trapping roaches, you can flush them down your toilet for sanitary disposal. If your homemade trap isn’t working, consider purchasing one. Traps have the added advantage of letting you discover where the roaches are congregating in your home—the traps with more bodies are in the more populated areas, which may need additional treatment.
Boric acid
Boric acid, used as an insecticide in powder form, works by abrading the cockroach’s cuticle, or shell, with its harsh particles. When its shell is damaged, the insect will dry out and ultimately die of dehydration. This is an effective method, but may be less useful in highly humid environments where it will take the cockroach longer to lose its moisture. Some people recommend making a paste by mixing boric acid powder, flour or sugar, and water; the starches make the mix more food-like and thus more attractive to the roach.
Bait stations
Many companies offer bait stations, which are similar to live traps but work by incorporating a deadly mold in the bait. This mold is harmful only to cockroaches and related insects and should not be damaging to humans or pets. Other traps may incorporate pheromones to attract the cockroach into the trap to ingest the mold or another type of poison. Stations usually provide an enclosed environment that is attractive to the cockroach, which prefers dark, tight spaces.
Sprays
Sprays can be classified by the type of insecticide they use. Common chemicals used to kill cockroaches include permethrin, imiprothrin, and cypermethrin. Some sprays are liquid, and others are powder; the powders tend to be both more toxic and more lasting, as well as capable of covering a larger area.
TIP: Don’t spray and use bait stations or traps simultaneously. The sprays will make the bait less attractive to the roach and eliminate its enticing powers. Bait stations can be better for bigger infestations, so start with stations and spray for regular upkeep once the roach population has been reduced.
Gels
Gels or “sticky traps” are strips of gel or other sticky substances, designed to catch cockroaches on their way in or out of your home. The roaches will be unable to escape from the stickiness. In addition to helping get rid of roaches, these sticky strips can also help you identify where roaches live and move in your home, so you can treat highly populated areas more aggressively.
NOTE: Cockroaches prefer to walk so that the sides or tops of their bodies are touching another object, like a wall or the bottom of a piece of furniture. (This trait is called thigmotaxis or stereotaxis.) Keep this in mind and place your sticky traps next to walls or under or next to low furniture items or cabinetry.
Insect Growth Regulators (IGRs)
While most insecticides attack the cockroach’s nervous system, IGRs work to sterilize immature cockroaches so they will not be able to reproduce as adults. Adding IGRs to your treatment plan helps ensure that both the current and future cockroach populations will be eliminated. Since fast reproduction is a major reason roach populations become and stay so large, eliminating this factor is a big boon in roach control.
By using a combination of these methods, you can eliminate the vast majority of any cockroach population from your home. Once you’ve significantly reduced the number of critters around your apartment, your next step is preventing these pesky buggers from returning.
