Final answer:
The insect you found on your wooden floorboards is a house mite, a common arthropod in household dust that feeds on organic debris.
Step-by-step explanation:
The insect you found on your wooden floorboards in Athens, Greece is a common house mite. House mites are small arthropods that feed on organic debris, including human skin. They are commonly found in household dust, and their feces can trigger asthma attacks. Despite frequent cleaning, it's difficult to eliminate them entirely.