Once you've found roach nests, make your own roach poison by combining one part boric acid with one part both white flower and white sugar. Put this mixture anywhere you suspect roaches are living.
You can also purchase spray insecticides specifically designed for roaches. Plastic cockroach traps lined with chemical poison are also affordable and can be hidden discreetly in corners and under appliances.
Take a jar filled with water or coffee grounds and set it against a wall. Roaches will be lured into the jar, but won't be able to escape.
Pesticide companies can spray powerful liquid poison concentrate in homes with serious cockroach infestation.
Once you've gotten rid of the roaches, take a few steps to prevent their return. Keep cooking and food storage areas clean, as cockroaches love grease and dirty dishes. The same goes for trash disposal areas. Cockroaches love water, so make sure your faucet isn't dripping and your sink is wiped clean. If you step on a pregnant female, dispose of her thoroughly, as her eggs will still hatch and grow after her death.