It is easy to transport them from house to house and even across oceans. Prevention and control are important in the fight to eliminate cockroaches. Killing only the ones you see is not effective, because if you see one there is 300 in hiding. To eliminate them in your house you have to get rid of their food and water, eliminate the present population with a poison and prevent future cockroaches from invading your house. Always plug drains on sinks when not in use.
Cockroaches can t swim but they can come in through sewer pipes if the water has subsided.
Keep counters, floors and cupboard free from food and crumbs. Insecticide sprays can be used to control cockroaches. You can call out a professional and pay for the service to your home. You can also spray yourself with an insecticide you buy at a home center. You have to make sure you get all the hiding places, cracks, crevices, baseboards and under sinks.