They can also get over from neighbors through ventilation or cracks in the walls.
📌 How to get rid of them:
Do a deep cleaning, vacuum all cracks, seams and joints. Wash linen and clothes at a temperature of at least 60 °C.
Use a steam cleaner on the mattress and furniture. Contact a professional pest control service – otherwise there is a risk that the bedbugs will return.
Now I understand – if I had not noticed these “grains” today, in a week I would have had a whole army of these parasites in my house.