Cockroaches can be a problem in Spain I once had a friend in Madrid and when we went up the dimly lit stairs after a night out our shoes crunched on cockroaches on every step, disgusting!!!
In the south of Spain mid May is the worst time of year for cockroaches because they like warm temperatures and at the onset of summer they go exploring in search of new sources of food and for new places to live. It is at this time of year that people may notice cockroaches scuttling around in their houses. Most people are horrified to see a cockroach and will immediately go out and buy anti cockroach devices in the supermarket. The most common device is a small plastic roach trap which contains some poison, also they are aerosol sprays. The problem is that almost immediately the problem gets much worse because many dead or dying cockroaches appear.
Normally the cockroaches are nocturnal and in a domestic house they come out at night and feed on crumbs and food that has been left out. Cockroaches prefer dark places and can live for a long time without food and with little water. Many people are unaware that they actually have a cockroach problem because the cockroaches can hear you coming and hide before they are seen. So it is very important to maintain scrupulous cleanliness in the kitchen. Never leave food out, always clean crumbs away and don't let anything edible remain on the floor especially in difficult to access places such as the side of a cooker. It may be a good idea to do a deep clean of your kitchen to make sure that there is nothing edible under the kitchen units or the fridge etc. I once lived in a house in the Albaicin and on a couple of occasions 15 or 20 dead or dying cockroaches appeared in the bathroom. Outside the bathroom was a drain cover that had a gap in it. I went to the hardware shop and bought some fine plastic mesh and stuffed it into the hole. There were hundred of roaches in the drain, the only way to stop them was to make a physical barrier. So make sure that it is impossible for a cockroach to enter your house. This is never 100% certain because they can fly.
The problem if you have airbnb guests is that if you use poisons the problem will get worse before it gets better because your guests will see dead and dying cockroaches. A way around this is to use a non poisonous trap. The best one I have used is the Vegas Roach Trap. It can be as simple as a large glass with some water, sugar and coffee grounds in the bottom. The roaches climb into the glass and then drown in the water. Just put "Vegas Roach Trap" into google there are plans for much more complicated ones. Put the trap in a place that can't be seen like a locked cupboard and empty it every few days. If you have a bad infestation you can get 10 or 15 cockroaches in a night using that method.
You will have to accept that is you live in Spain you will probably never completely get rid of cockroaches, there will always be 2 or 3 every year. People who come from the north of Europe will be freaked out just by the sight of one cockroach. You could say that if you can't cope with the occasional cockroach don't come to Spain. On the other hand any householder should take all steps to eradicate them and if you rent your house out the guests you will have to be very vigilant. In other parts of the world they are eaten as a delicacy.
Common household cockroaches
A) German cockroach
B) American cockroach
C) Australian cockroach
D&E) Oriental cockroach (♀ & ♂)
