Yeah if you see one there are high chances that he is not alone. They are commonly found at late night when you open your kitchen light at night you will see a lot of them together. Cockroaches carry some bacteria with them and if some food is in the kitchen then they are high chance that they will be left some bacteria on it. So when you see them you have to remove all the food from the kitchen and keep them in the fridge with tight packing so that they can't find a way to get inside. The last step will be the cockroach control service to get rid of them.