Spiders belong to the class Arachnida, the most numerous order of arachnids, with more than 40 000 described species. They can also penetrate indoors, their presence being detectable through woven webs. In order to avoid their appearance, it is necessary to keep clean and to remove dust from all surfaces. If the presence of webs is discovered, it is advisable to remove them, vacuum and wash the area. Treatments are carried out with specific insecticides, which are chosen according to the space treated (indoor/outdoor).