Cockroaches are mostly attracted to dirty houses but it's possible to have roaches come into your house even when you keep your house really clean.
Roaches are a natural part of the earth and naturally roaches will be attracted to your home because they figure there's food in your home.
The roaches can still get into your house through tiny cracks, holes etc in your house and then after they get in they multiply by giving birth too thousands of roaches.
If you notice one roach getting into your house you need to kill it before it multiplies.
Once you get a huge roach infestation it can be hard to get rid of them without the use of an exterminator.
I have a really clean house myself and get a few roaches from the outside although I kill them right when I see them.
I haven't had a roach infestation since doing that.
I would recommend getting an exterminator to come in and kill the roaches in your house and also kill the roaches that are outside.
Seal any cracks, holes etc that the roaches may get into your house through.
Also make sure there is no moisture, crumbs and other tiny food debris around such as on your tables, floors and even your counter.
Keep your sink dry as well as the roaches are also attracted to your sink because of the moisture as well.
If you live in states such as Arkansas, Kansas, Florida, Georgia or Alabama then you are bound to get roaches no matter what.
The key to getting rid of roaches is to kill them before they multiply.
Also you can use baking soda and sugar to kill roaches naturally as well.