Fabric furniture: sofas and chairs
Various allergens can often be found on fabric furniture and pillows. If there is a dog or cat in the house, you will especially encounter a lot of animal hair on chairs and sofas. Not only because a pet often sits on this; the animal hairs can adhere more easily to fabric than to smooth surfaces.
It can be a good idea to thoroughly vacuum and clean your sofa every now and then to prevent it from becoming a source of allergens. Don't forget the gaps between the cushions.