Why are they called “flea markets”?
Etymologists do not agree on an undisputed source. Some attribute “Flea Market” to the outdoor bazaar of 1880s Paris, France which was described as “le marché aux puces” which literally translates into “Market of Fleas”. This is a supposedly derisive term indicating that articles sold there might be infested with fleas.
Can you bring fleas into your home by buying used articles? A review of the biology of the cat flea says, “Yes”. The cat flea is the most common flea found on dogs and cats in North America. The adults colonize a cat or dog, mate, feed and excrete copious amounts of blood in their feces which are food for the larvae. The flea eggs are laid by the female, but do not attach to the animal. The eggs roll off the animal and onto pet bedding carpet, or any article of clothing underneath places the animal rests.
The larvae hatch and generally feed in the carpet or in cracks in the floor. So if a flea market vendor has a cat or dog that sleeps on carpets or other wares, then yes, those items could contain larvae or pupae of fleas. Bringing flea infested items into your home could result in a flea infestation. Generally, flea infested items will have some mature fleas ready to jump on a host in response to heat. Thus, a potential buyer (or observant critic) could detect the presence of fleas and call them “Flea Markets”.