You can get infested by cat fleas by being in contact with infested pets, or by being in places where infested pets are or have been. Cat fleas, however, prefer their natural host animals such as dogs or cats. Consequently, the family pet can have fleas without the other family members noticing. For this reason, there is no risk of infecting other people at work or school with fleas, even if there is a pet with fleas in your home. The risk of being bitten is high if the dogs or cats are removed, and the fleas only have access to human blood – or if you are in places where dogs or cats are kept, and where the hungry fleas are now sitting and waiting for something to bite.
The may be in an empty apartment where the previous resident had pets, or in cellars and outbuildings where semi-feral cats have lived. After a vacation, it is also typical that many fleas when returning to a house where a large number of fleas have hatched while you were away attack you. In a house with cat fleas, flea bites are often seen equal frequent in children. On adult humans, flea bites are mostly common with women (2/3) and not as common with men (1/3). The cause of this phenomenon is not known.