When we checked in we found mice fecies in many places around the house (even on our bed sheets) and even worse, mice were in the house. When we moved the couch in the living room, we found that there was rat poison behind it, which had been eaten by the mice. Montse had layed out rat poison there preemptively, because the house had not been rented out in a longer time - this is fine. What is not fine however, is not checking if the rat poison had been eaten by mice or rats.
When we confronted Montse about this, she told us that it was not her job to check if the poison had been eaten by any vermin (even though she obviously layed it out preemptively) and said that it was the cleaning lady's job, which she hired to clean after each stay. However it is obviously her job as a host to ensure that atleast the lowest hygienic standards are met in the listing , in this case not having mice live in the house.
When we asked her about calling an exterminator, she told us that it was not possible to call one because the next day would be a holiday in Spain, which was correct, however she also told us that it would not be possible to get an exterminator the day after the holiday (also because of the holiday), which sounded like an excuse and seemed like she just didn't want to spend any money on the problem.
What I have to give her credit for, is that after we messaged her about the mice fecies in the house and on our bed sheets she came over the same day to bring us fresh bed sheets.
In total however I have to say that the way Montse handled the situation was very unprofessional.
Laying out rat traps and then renting out the house without checking if the rat poison had been eaten by rats or mice and then telling us that it was not her job to check and nothing could be done about it is very unprofessional.
On top of that I cannot verify if Montse actually did not know about the mice (so I have to believe she did not) but because she did lay out rat poison, I am skeptical of this and if she did know about the mice, then renting out the house would be downright fraud.