Your cat darts across the carpet like it’s a bed of hot coals. Your dog has become a 24/7 scratching machine. You find red, itchy bite marks on your body when you wake up.Fleas can attach themselves to animals outdoors, move indoors with you, jump from one pet to another, spring from carpets or upholstered furniture, or hatch from dormant larvae in your home. They can live year-round indoors, and outdoors as well in warmer climates.