In tropical and subtropical climates, mold fungi can grow on the walls of homes due to water seepage and moisture. To prevent this, the walls can be covered with ceramics or cleaned when necessary. Chemical and dehumidifiers can also be used to reduce humidity to below 50% and to filter out large fungal spores. However, the use of air conditioning and the insulation of windows can cause increases in exposure to mold and dust mite allergens. If it is clearly understood that children's complaints are related to mold sensitivity and mold allergy, moisture reducing devices can be used. It should not be forgotten that potted plants, aquariums and bird cages in homes can also be a source of mold.